Merchant's House Museum

The Merchant's House Museum, also known as the Old Merchant's House and the Seabury Tredwell House, is a historic house museum at 29 East Fourth Street in the NoHo neighborhood of Manhattan in New York City. Built by the hatter Joseph Brewster between 1831 and 1832, the house is a four-story building with a Federal-style brick facade and a Greek Revival interior. It served as the residence of the Tredwell family for almost a century before it reopened as a museum in 1936. The Merchant's House Museum is the only nineteenth-century family home in New York City with intact exteriors and interiors.

Brewster built the house as a speculative development and sold the house in 1835 to the merchant Seabury Tredwell, who lived there with his wife, eight children, four servants, and several relatives. Five of the children never married and, for the most part, lived at the house through the end of the 19th century. The house remained in the family until the death of the youngest child, Gertrude, in 1933. George Chapman, a distant relative, purchased the building and transformed it into a museum. Over the next three decades, the museum's operators struggled to obtain funds to restore the deteriorating house. The architect Joseph Roberto completely renovated the house from 1970 to 1980, and the museum underwent further restoration in the early 1990s after the demolition of nearby buildings damaged it. During the 2010s and 2020s, museum officials fought the construction of a nearby hotel because of concerns over the house's structural integrity.

The house has a raised basement, an ornate doorway accessed by a stoop, a slate roof, and a rear garden. The interior consists of a family room and kitchen in the basement; two parlors on the first floor; and bedrooms on the upper floors. The museum's collection has over 4,500 items owned by the Tredwell family, including pieces of furniture, clothing, household items, and personal items. The museum also presents various performances and events at the house, and it operates tours and educational programs. Reviewers have praised both the museum's exhibits and the house's architecture. The house's facade and interior are New York City designated landmarks, and the building is a National Historic Landmark.

Site
The Merchant's House Museum, originally the Seabury Tredwell House, is at 29 East Fourth Street in the NoHo neighborhood of Manhattan in New York City. It is on the north side of Fourth Street, between Lafayette Street to the west and Bowery to the east. The land lot is rectangular and measures 3072 ft2, with a frontage of 24.25 ft and a depth of 128.83 ft. The current museum was built as one of six identical houses on the same block.

Abutting the museum to the east is a public park named Manuel Plaza. Several doors east of the museum, at 37 East Fourth Street, is the Samuel Tredwell Skidmore House, a three-story Greek Revival house built for a cousin of one of 29 East Fourth Street's early residents, Seabury Tredwell. The Skidmore House was the residence of Skidmore, his wife, eight children, and a nurse. Designated as a New York City landmark in 1970, the Skidmore House was restored by 2010 after falling into disrepair. The De Vinne Press Building to the west, and the Astor Library (also known as the Public Theater) to the north, are on the same block. Other nearby buildings include the Firehouse of Engine Company No. 33 one block south; 357 Bowery half a block east; and the Schermerhorn Building half a block west.

The site of the house was historically part of the estate of German-American businessman John Jacob Astor, who in 1803 acquired land between what is now Astor Place and Great Jones Street. Astor subsequently built his mansion and horse stable directly to the west of the Seabury Tredwell House. In the 1830s, the wealthiest New Yorkers were starting to relocate northward from what is now the Financial District of Manhattan to what is now Lafayette Street in NoHo. At the time, the area surrounding Lafayette Street was still mostly undeveloped. Residential development in the area peaked at that time before moving northward in the 1840s and 1850s.

History
Seabury Tredwell was born in 1780 to a prominent Long Island family; he was a descendant of Samuel Seabury, an Episcopal bishop. Tredwell established a business on Pearl Street in Lower Manhattan around 1803 or 1804, which later became Tredwell, Kissam & Company. Tredwell married Eliza Parker in 1820, and the couple had seven children (five girls and two boys) over the next fifteen years, before Tredwell retired in 1835. Although Tredwell had been a successful businessman during his career, he was not well known outside of his community.

19th century
Joseph Brewster, a hatmaker who also developed speculative real estate projects, acquired two land lots in 1831 for a combined $6,550. On one of these land lots, he built a townhouse at 29 East Fourth Street. The architectural writer Donald Reynolds wrote that Brewster finished the house in April 1832 and lived there for three years. Reynolds sold the house in 1835 to Tredwell for $18,000. The house remained the Tredwell family's residence for nearly a century. The Tredwells attended the nearby St. Bartholomew's Church and occasionally went to Central Park to drive on the carriage trails there. They vacationed in New Jersey during the summer but lived on Fourth Street the remainder of the time, shunning publicity. Tredwell's youngest daughter, Gertrude, was born in the house in 1840. Gertrude, her two brothers, and her five sisters all lived in the house with their parents.

The family employed four servants at any given time; almost all were Irish women, and they never worked more than a decade. Relatives of the family occasionally stayed at the house when they had nowhere else to stay. In the 1850s—after the second-youngest daughter, Sarah, was severely injured in a stagecoach accident—a hand-pulled elevator was installed in the house to bring Sarah to her bedroom, and the staircase to the third floor was rebuilt. The house was also one of the first in New York City to receive gas from the Consolidated Gas Company (later Consolidated Edison) in the mid-19th century. Seabury died in 1865, leaving each child $10,000. The family remodeled their house two years later.

Only three of the Tredwells' children married and moved out of the house; four daughters and one son never married. Eliza Tredwell died in 1882, followed by the siblings' unmarried brother in 1884. By then, many of their wealthy neighbors were moving away. The New York Times and the New York City Department of Parks and Recreation indicate that it was not known why the family remained, but the Toronto Star wrote that the Tredwells were too poor to move uptown. The unmarried sisters—Julia, Phebe, Sarah, and Gertrude —remained in the house as spinsters. They gradually upgraded the furniture, although the sisters wished to retain the furnishings "as Papa wanted it". With no income, the sisters subsisted on their father's estate, selling off land in Brooklyn and New Jersey as money became scarcer. Sarah eventually moved to the Cadillac Hotel near Times Square, where she died in 1906, leaving just Phebe, Julia, and Gertrude at the house. According to Seabury Tredwell's great-nephew George Chapman, the family was "not a friendly lot".

Early 20th century
By 1909, three of the remaining sisters had died. The only surviving sister, Gertrude, had reportedly become a recluse after her father banned her from marrying a Roman Catholic physician. Gertrude hired a maid who greeted the few visitors that she received. At one point, Gertrude had a conflict with the Consolidated Gas Company, which, in recognition of the Tredwells' early adoption of gas, had allowed the family to pay their gas bill less frequently than other clients. According to the New York Herald Tribune, a "young and inexperienced bill collector" once cut off Gertrude's gas in the mistaken belief that the family had not paid their gas bill. A director from the gas company later showed up to apologize, only to be told after an hour that Gertrude would not speak with him.

In her final two decades, Gertrude increasingly stayed in her second-floor bedroom because of her declining health, and one of her nephews moved onto the third floor. They mostly stayed in the house, going to Lake Champlain for a few weeks every year. Burdened with severe financial hardship, Gertrude was forced to sell her belongings and take out a mortgage on her home. Nonetheless, Gertrude preserved the house in its original condition, long after all the neighboring private homes had been demolished or converted to other uses. Electricity, running water, and a furnace were installed around 1930. After her nephew died that year, Gertrude seldom had visitors, and she died alone in one of the second-floor bedrooms in 1933. The New York Times wrote that Gertrude had died as "a gentle, well-bred [recluse] hemmed in by ugliness — and she had been forgotten". The house was unoccupied for the next several years. Although Gertrude had been poor at the time of her death, the house still retained many of the family's possessions. Visitors claimed that the house was haunted by Gertrude's ghost, a legend that persisted in the late 20th century.

Use as museum
After Gertrude's death, Eliza Nichols, the daughter of Gertrude's oldest sister Elizabeth, wished to pay off the house's mortgage by selling both the structure and the objects inside. George Chapman purchased the building, saving it from foreclosure and demolition. According to The New York Times, Chapman's acquisition had taken place "the night before the house and its furnishings were to go on public auction". He formed the Historic Landmark Society, which acquired the house and converted it into a museum called the Old Merchants' House. The new name was intended as a tribute to New York City's early merchants, including Seabury Tredwell. Chapman's wife cleared out enough objects to fill two vans; these objects were then placed on display in the house. The Tredwells' items, clothing, table settings, and furniture were all displayed in their original condition, or as close to it as possible.

1930s to 1960s
The society held a private reception for the museum on May 8, 1936, and formally opened the museum three days later on May 11. The museum was initially was open from 11 a.m. to 5 p.m. every day. The New York State Education Department installed a plaque the same month, commemorating the fact that the house had been Seabury Tredwell's residence. The same year, numerous photographs of the house were taken as part of the Historic American Buildings Survey, and photos of the interiors were exhibited at Columbia University's Avery Architectural and Fine Arts Library. The Historic Landmark Society launched a fundraising campaign in 1943, seeking to raise $100,000, but had received only $7,000 within two years. At the time, the society spent $3,500 annually just to operate the museum, but its 50-cent admission fee and 2,500 annual visitors were not enough to pay the operating costs. This led Chapman to warn that the house was in danger of being sold. Ultimately, Chapman managed to pay off the mortgage, and he continued to operate the house as a museum. The museum's caretakers, married couple Harry Lundberg and Florence Helm, lived in the basement; Helm lived there until her death in 1954.

The museum attracted 1,000 visitors annually by 1950. The next year, the Historic Landmark Society's board of directors convened to discuss the endowment fund, which had grown to $25,000 but was still short of its goal. The Boston–based Hale Foundation promised to donate $45,000 if the museum's operators were able to match the donation, but this did not happen. Consolidated Edison installed a gas-heating system in the museum in 1955. By the early 1960s, the house was in very poor condition and needed $200,000 in repairs. According to architectural critic Ada Louise Huxtable, the house was so weak that a severe storm could potentially destroy the plaster ceilings, and the original furnishings were "ready to crumble on a touch". The museum still did not have enough visitors to finance its own operation. Museum officials had unsuccessfully attempted to obtain funding from private donors, and Randolph Jack, its curator, was personally paying for the museum's upkeep.

Jack indicated in early 1965 that the house and the objects inside might be sold to raise money. The New York City Landmarks Preservation Commission (LPC) described the house as "a document of great importance for its authenticity" but, at the time, had no legal power to preserve the house. Following this announcement, preservationists asked both federal and state officials to protect the house as a landmark, and a hundred children protested the house's planned demolition. Architects also proposed alternate uses for the house to preserve it, and hundreds of people testified in defense of the house at a hearing for the city's landmarks law. That October, the LPC designated the house as one of the first-ever official city landmarks.

1970s renovation
In the late 1960s, the museum tried to raise money for a restoration through events such as a tour of Staten Island. The Decorators Club expressed interest in restoring the house, and the museum was closed for some restoration work during August 1968. The club hired Joseph Roberto, an architect employed at the nearby New York University, to consult on waterproofing issues. The club had raised $5,000 at the time, all of which was used to restore the cornice. Although Roberto wrote various letters to officials, asking them to fund the house's restoration, the project did not attract further attention until 1970, when Huxtable wrote about the house. The New York City government and the New York State Historic Trust provided initial funding for the renovation in 1970. The Historic Trust gave the museum $30,000 in 1971, matched by numerous private and public donors, and it distributed another matching grant of $12,000 in 1972. The trust provided another matching grant of $35,000 in 1975, and the house also received funding from the federal government.

Roberto designed the house's renovation, donating about $500,000 worth of services. Also involved in the project was Joseph Roberto's wife Carol, an interior designer. The Robertos, along with six other people, were named as museum trustees. Structural and exterior work began in 1972 and was completed in three phases. The project involved rebuilding the foundation, replacing more than 2,500 bricks along the party walls, replacing the slate roof, and reattaching the facade to the inner wall. The ceilings of the drawing rooms, which were physically beginning to peel apart due to vibrations from traffic, were tied together with wire. Interior work commenced as part of a fourth phase in 1974; about $100,000 was allocated to restoring the interior and adding plumbing, heating, and electrical wiring. The furniture was restored; one carpet had to be completely replaced because of its tattered condition. Restoration workers examined several layers of paint before restoring the walls to their original off-white color. Other objects such as lighting fixtures were also restored, and Lawrence Majewski was hired to refurbish the cast iron railings.

At the time of the renovation, the city-landmark designation only extended to the exterior, so there were concerns that the house's interior could be significantly altered during the renovation. The city was in the midst of a severe fiscal crisis, leading the Christian Science Monitor to describe the renovation as "a bright spot in these sad times for New York City". The first floor reopened in November 1979, and the museum received an additional $70,000 in donations to refurbish the second floor. Museum officials held a Christmas party in 1980 to mark the completion of the second-floor renovation. The project had cost $280,000, funded by over two dozen donors; at the time, museum officials planned to spend another $100,000 to restore the kitchen and bedrooms. The same year, Joseph Roberto received a certificate of merit from the Municipal Art Society for his work on the house's restoration. The Robertos continued to work in an office at the front of the house.

1980s and 1990s
After the museum reopened, the basement, first, and second floors were open to the public on Sunday afternoons, and groups were allowed to book appointments during weekdays. Members of the public could also visit the garden in the rear. The New York Times wrote in 1987: "The house is very much alive these days with its occasional use for special events and celebrations." The owner of three small buildings just east of the Seabury Tredwell House, at 31 to 35 East Fourth Street, announced plans in late 1987 to destroy these structures. The structure at 31 East Fourth Street shared a party wall with the house, which was to remain partly intact. Following the demolition of these buildings the next year, the house experienced $1 million in damage. Because of the lack of a retaining wall to the east, a crack formed along the length of the house, and the interiors suffered water damage. When Joseph Roberto died in 1988, the museum began searching for new staff.

The museum hired several staff members in April 1990, including executive director Margaret Halsey Gardiner. According to Gardiner, the museum spent $600,000 to stabilize the house. The sculptor David Flaharty was hired to restore the interior plasterwork, and architectural firm Jan Hird Pokorny was hired to research the house's history and architecture as part of the museum's master plan. In addition, researchers began excavating the backyard for archeological studies of the Tredwells. After a renovation lasting eight or nine months, the museum reopened in December 1991. Under the auspices of the New York Landmarks Conservancy, in 1994, workers removed graffiti that had accumulated on the house's facade. The Vincent Astor Foundation gave the Merchant's House Museum a $1 million grant in 1997, and the museum joined the Historic House Trust of New York City in the late 1990s.

2000s to present
During the early 21st century, the museum hosted tours of the surrounding neighborhood to raise money, since it was susceptible to changes in New York City tourism numbers. By the 2010s, forty volunteers operated the museum, which had 15,000 annual visitors. The surrounding neighborhood had become a fashionable residential area. An analysis from The Wall Street Journal found that, if the building were still functioning as a residence, it could be sold for $6 million in 2018.

In 2012, Kalodop II Park Corporation proposed an eight-story hotel immediately west of the house. Because the hotel's construction could impact the house's structural integrity, the LPC was required to review the plans. The hotel's developers promised that the development would not damage the museum and stated that the new building would structurally reinforce the museum. The LPC eventually approved the hotel in 2014 after rejecting three earlier plans. The LPC formed a plan to preserve the museum while the hotel was being constructed. Gardiner opposed the hotel's construction, and preservationists also spoke out against the project, claiming that the hotel's construction could destabilize the house. According to one museum guide, the plaster moldings could be damaged irreparably if the house tilted 0.25 in.

Gardiner submitted a petition to the New York Supreme Court in early 2018, claiming that the New York City Department of City Planning had approved the hotel project based on erroneous information from Kalodop. Gardiner claimed that the hotel's construction could cause the house to collapse, and museum officials put up signs warning that the museum could be bankrupted by increasing legal costs. Gardiner formally sued the DCP and Kalodop in mid-2018, and a subcommittee of the New York City Council voted against the hotel plans that September. Kalodop then sued to reverse the City Council's decision, claiming that they planned to ensure that the house would not be damaged. The developer filed new plans for the hotel in late 2020, but the LPC delayed a decision over these plans because of concerns over the house's structural integrity. When the hotel was approved in late 2023, Gardiner said that vibrations from construction could cause "irreparable" damage and threatened to sue. As the dispute over the adjacent hotel development continued, NYC Parks was planning to renovate the Seabury Tredwell House for $3.2 million starting in late 2024.

Architecture
Though parts of the house's design may have been derived from books of architectural patterns published in the 1820s and 1830s, no single architect has been credited with the design of the Seabury Tredwell House. The National Park Service (NPS) credits Menard Lafever with the house's design, while the historian Barbaralee Diamonstein-Spielvogel writes that Joseph Brewster, who built the house, was inspired by Lafever. In his 1964 book Greek Revival Architecture in America, the architectural critic Talbot Hamlin wrote that the plaster and wood decorations of the house were similar to a set of patterns that Lafever had published in 1826. Reynolds said that three of Lafever's pattern books inspired parts of the house's design. The Chicago Tribune claimed in 1957 that John McComb Jr., who had designed New York City Hall, also designed the mansion.

The house has a Federal-style facade and a Greek Revival interior. Vogue magazine identified the design in 1941 as being a mixture of the Empire and Victorian styles, while The Christian Science Monitor described the house's design in 1945 as being "mainly of the late Georgian period". A Chicago Tribune critic said in 1954 that the house was "the purest example of the so-called Federal style in New York". The NPS's report on the building describes the house as being designed in a transitional Greek Revival style. Ada Louise Huxtable of the New York Times described the house as "cross[ing] the border between Federal and Greek Revival, tipping well toward Greek Revival". Town & Country magazine, in 1981, also characterized the exterior as a mixture of the Federal and Greek Revival styles but said the interior was "decidedly" Greek Revival. Diamonstein-Spielvogel and journalist David W. Dunlap describe the exterior design as Federal.

The Seabury Tredwell House is likely the only house in New York City with a fully preserved 19th-century interior, as well as one of the few late-Federal-style houses in the city that have not undergone significant changes to their design. By the 1980s, the Seabury Tredwell House was Manhattan's only remaining 19th-century house that retained its original furnishings.

Exterior
The exterior of the Seabury Tredwell House is four stories high and is divided vertically into three bays. The basement is raised, so the first story is half a floor above ground. The facade was identical to that of the five other houses developed by Brewster, as well as three houses at 585, 587, and 589 Hudson Street, which Archibald Falconer's estate had developed in 1833; these houses have since been demolished. Another house, on 56 West 10th Street, was a smaller replica of the Seabury Tredwell House. To the west and east of the house are party walls made of brick; these party walls were originally shared by the houses on either side.

A decorative iron railing separates the house from the street and is decorated with finials and caged newel posts. On the eastern side of the facade, a flight of six steps with iron railings leads up to the main entrance. There are Ionic columns on either side of the doorway, above which is an arch with a large, semicircular fanlight. On the cellar and the first through third floors, the facade is made of brick. The fourth floor is placed within a steeply sloped gable roof made of slate tiles. There are two protruding dormer windows on the fourth story.

At the rear of the house is a wood frame annex built in 1850, with a stairway leading from the first floor down to a small garden. There is a toilet under the steps and a cistern in the yard. Another stair leads up from the basement to the garden. The cistern, with a capacity of 4000 gal, predates the Croton Aqueduct's construction. In addition, the garden had four magnolia trees in the mid-20th century. The garden has been modified over the years, but it contained typical 19th-century plants by the 2000s. Some of these plants, including vinca, columbine, and black-eyed Susan vines, were grown from specimens that had been excavated from the garden. , the garden is open to the public but accessible only from the basement.

Interior
According to the New York City Department of City Planning, the building's gross floor area is 4218 ft2. The Seabury Tredwell House has a similar layout to many 19th-century rowhouses in New York City. The basement contains the kitchen and family room, and the first story features the formal double parlors. There are bedrooms on the second through fourth stories; the bedrooms on the top story were used as servants' quarters. There was also a coal room below the basement, which was converted into a heating plant at some point before the 1960s. In total, the house has about 18 rooms. Materials like Siena marble and plasterwork were commonplace at the time of the house's construction and were used throughout the building.

Basement
The raised basement contains two main rooms: a family room in the front and a kitchen in the rear. Between these two rooms were a pair of closets and a pantry (which were later converted into bathrooms and a kitchenette). All of these spaces are connected by a hallway on the eastern side of the basement, which extends the entire depth of the house. At either end of the hallway is a door with six panels, above which is a fanlight. A similar door with brass knobs leads from the basement hallway into the family room. There is a door halfway down the length of the hallway; it was added sometime after the house was completed.

The family room is decorated with peach-colored walls topped by plain cornices. There is also a sash window on the family room's south wall and a fireplace with a black-and-gold marble mantelpiece. The family room, which functioned as a sitting and dining room, was also used for other activities such as sewing, reading, writing, and mending clothes. It was inaccessible to the Tredwell family's visitors and, as such, did not need to be as tidy as the other rooms in the house. After the house was converted to a museum, the family room was converted into a children's playroom exhibit.

The kitchen features built-in Dutch ovens and a fireplace. The kitchen originally had a dumbwaiter, stove, and sink; these were removed in the 1930s when the house was converted to a museum, but a coal range and a sink had been re-added to the museum by the 1980s. The floors are made of wood. The fireplace is on the kitchen's western wall, with the sink to the right and a closet to the left of the fireplace. The sink had a hand pump, which drew water from the backyard cistern. There is also a brick oven and a cast-iron stove on this wall. On the kitchen's other three walls, the lower portions are wainscoted with wooden boards, while the upper portions are made of plaster. The eastern and southern walls have bells for servants.

First story
The Seabury Tredwell House's main entrance leads to a square vestibule with a floor of black and white marble, as well as walls painted to resemble authentic Siena marble. The walls of the vestibule were painted using turkey feathers. Atop the walls of the vestibule is a cornice with a molded egg-and-dart motif, which supports a ceiling with a central rosette made of plaster. At the north end of the vestibule is a door leading to the main first-floor hallway. The door is divided into eight mahogany panels, which are flanked by sidelights; this is topped by a fanlight and a keystone with acanthus leaves.

The main hallway runs along the eastern side of the first floor. The hallway is decorated with a plaster cornice containing egg-and-dart moldings, as well as a ceiling rosette with a cut-glass lantern. There is a stair to the second floor on the right side of the hallway, as well as a door underneath the stair, which leads to a tea room. To the west of the main hallway are the two parlors. The parlors are accessed by three mahogany doors, which are flanked by classically styled pilasters and topped by a lintel with egg-and-dart motifs. The parlors were intended to have a symmetrical design; as such, both rooms have two doorways on their eastern walls, but one of the front parlor's doorways is a false door. Both rooms also have 14 ft ceilings and full-height six-over-six sash windows facing north and south. The rooms are connected to each other by an arched partition flanked by Ionic fluted columns, which shield a sliding mahogany door between the rooms. The sliding door originally had silver-plated trim. The bases of these columns are octagonal in shape, while the capitals are decorated with anthemia. Each of the parlors also has wide wooden baseboards and a cornice with alternating bands, egg-and-dart motifs, and foliate decorations. There are fireplaces in both rooms, with coal grates, white marble hearthstones, and mantelpieces made of Belgian and Italian marble. In addition, the ceilings of each parlor have deeply recessed rosettes, from which bronze chandeliers with glass globes are suspended; the original gas-powered chandeliers were connected to the city's power grid in 1935. The floors are covered with replicas of a moquette carpet that the Tredwells once used.

There is allegedly a secret passage in the wall between the two first-floor parlors, which leads up to a drawer between the second-story master bedrooms. A New York Herald Tribune article from 1938 was unable to ascertain when or why the passage was built. According to the LPC, there are several unfounded rumors regarding the passageway, including claims that it connected to the street; was used to sneak suitors into the house; or was used to shelter fugitive slaves as part of the Underground Railroad. An LPC report indicates that the passage likely was used to facilitate the maintenance of the sliding parlor doors if they were knocked out of alignment. A museum curator said in 1965 that the passageway terminated in a dead end.

Upper floors
A hallway extends the entire depth of the second story and is illuminated by a lamp made of cut glass and etched glass. There are three bedrooms on this story. The front of the house contains a "hall bedroom" to the east and a master bedroom to the west, while the rear of the house contains another master bedroom to the west. The hall bedroom is the smallest of the three bedrooms and was also used as a study. Its doorways and window frames have blocks with carved acanthus leaves at their corners.

The two master bedrooms are accessed by Greek Revival-style doorways, which are flanked by pilasters and topped by lintels with decorative friezes, architraves, and cornices. Similar decorations are placed around the window openings, and there are two gaslit sconces on the walls next to each window. Each master bedroom has a fireplace with white hearthstones, veined marble mantels, and a coal grate. The cornices and plaster rosettes in the bedrooms are scaled-down versions of those in the first-floor parlors. The rear master bedroom has a straw carpet, and the two front bedrooms have a carpet with geometric patterns. Within these bedrooms, the family's original four-poster beds were preserved, complete with draperies.

Additional bedrooms were placed on the third and fourth floors. The third-floor bedrooms also have woodwork decorations, which are plainer in design than the furnishings on the second floor. The bedrooms on the third floor were used by the Tredwell family's children. On the fourth floor is a servants' living room and four bedrooms connecting with that space.

Staircases
The house's staircases are stacked atop one another. There is a staircase between the basement and first floor along the extreme eastern end of the house. At the basement level, there is a wooden-paneled wall separating the staircase from the basement hallway. At the bottom of the steps is a door and a brass bell mounted onto the wall. The staircase between the first and second floors has a mahogany handrail, supported by mahogany and brass spindles, and there is a bracket with tracery at the far end of each step. At the bottom of the handrail is a newel post, which is made of mahogany and carved with reliefs of acanthus leaves. The stairway is interrupted by a landing halfway between the first and second stories, which is illuminated by a tall window on the northern wall. At the top of the handrail is a post with a carved acanthus leaf, which, according to architectural critic Talbot Hamlin, was designed in a style characteristic of Duncan Phyfe.

Another staircase connects the second and third floors. The railing of this stairway has mahogany spindles and a newel post, which is decorated with acanthus wreaths only at its base and top. The design of the stairway dates to the 1850s when it was moved about 42 in north of its original location. This was done to accommodate a manually-pulled elevator that carried Sarah Tredwell to her room. Although the elevator no longer exists, it was supported by a rope and a winding mechanism in the attic, which are both still intact. , there are no elevators within the house.

Operation
The New York City Department of Parks and Recreation owns the house. The Merchant's House Museum is operated by Old Merchant's House Inc., a nonprofit organization dedicated to running education programs, conserving the collections, and restoring the house and the objects inside. The museum sells tickets for guided, self-guided, and neighborhood tours. There are explanatory plaques throughout each room, as well as docents throughout the museum. In addition, Old Merchant's House Inc. runs an online gift shop. Old Merchant's House Inc. has an endowment fund, which was established after the Vincent Astor Foundation disbursed its $1 million grant in 1997.

Collection
, the museum has almost 4,500 items in its collection. The items were broadly split into three categories. The oldest objects date to when Eliza and Seabury Tredwell married in 1820. The collection also features predominantly Greek-style items purchased after the couple moved to the house in 1835, as well as Victorian-style items purchased by Eliza after her husband's death. Following the museum's 1970s renovation, the museum has exclusively exhibited the Tredwells' personal belongings.

When the museum opened in 1936, it contained the Tredwell family's original furnishings. These included pieces from local cabinetmaker Duncan Phyfe; furniture upholstered with horsehair; tables with marble tops; red damask curtains that the family had kept in storage for six decades; and mahogany side chairs with red damask upholstery. A mahogany dining table and a dozen "balloon-backed" chairs are displayed in the two first-floor parlors. The house also had a music box, a grand piano made by Nunns & Fischer, oil lamps, cupboards with rare china, and brass doorknobs. Toys and clothes are displayed on the upper floors. In the 1980s, one of the master bedrooms on the second floor was described as having a "1835 mahogany canopy bed and a child's walnut field bed", while the other had a chintz bed.

The clothes in the collection include 39 dresses worn by Eliza Tredwell and her daughters. These included ball gowns that they wore as children; peignoirs that they wore to breakfast; and black taffetas that they wore in their middle age. Some of the clothes in the collection are from Gertrude Tredwell's trunks of summer clothing. As a child, Gertrude took twenty trunks to the family's New Jersey summer house every year, but the family servant eventually stored some of the trunks because Gertrude never wore the clothes inside. Objects such as combs, gowns, and fans were displayed in the walk-in closets, while mannequins with bonnets, gowns, gloves, and parasols were displayed in glass cases. A 1981 Town & Country article noted that the clothes on the mannequins were changed each season.

The collection also includes several household items. For example, the museum exhibited the family's cookware; 19th-century books and newspapers; and silver decorations. Tableware and mahogany pieces are shown in the parlor rooms. In the kitchen, objects such as the family's china collection and a pie safe were exhibited. Also on display are some needlepoint works that the Tredwells never completed.

Events and programming
Most of the museum's programming is educational in nature and includes courses on 19th-century culture. These courses are geared toward both youth and adults. In 1991, the Greenwich Village Society for Historic Preservation and the Merchant's House Museum launched an educational program called Greenwich Village: History and Historic Preservation. The program ran through the end of the 1990s at the museum, but eventually shifted its focus to the West Village. Since at least the 1990s, some archeological studies have taken place at the house.

Several events are regularly hosted at the house. The parlors regularly host music concerts. Nineteenth-century romantic music is presented every Valentine's Day, and the museum presents mock funerals with 19th-century theming during the fall. The house is sometimes redecorated with 1870s decor during the Christmas season. Throughout the year, the museum also hosts "ghost tours" by candlelight; since 2006, the tours have included vignettes of various family members, who are depicted by actors.

Over the years, the house has also hosted other events. It hosted a 1946 benefit for the American Friends of France, though in 1956 the museum's operators prevented Alfred Hitchcock from shooting a movie there. The house has been used for performances, such as the off-Broadway plays Old New York: False Dawn, Ellen Terry (A Public and Private Talk With Our Most Beloved Actress), and Bright Lights, Big City. John Kevin Jones hosted readings of Charles Dickens's novella A Christmas Carol at the house in the 2010s and 2020s, as well as readings of Walt Whitman's poetry. Other events at the house have included benefit dinners, summertime lunches within the backyard, open house celebrations, and parties.

Reception
Shortly after the museum opened, a writer for the Elmira, New York, Star-Gazette wrote that the house was "a marvelously authentic exhibit of the best of urban living", akin to the Morris–Jumel Mansion, because it showcased the family's actual artifacts. Vogue magazine wrote in 1941 that the museum had "a surprise in every closet", while a writer from the New York Times said in 1943 that the house's "graceful arrangement suggests a home actually lived in rather than a museum". A Times critic wrote in 1964 that the museum was "a 19th-century relic of bourgeois splendor". Ada Louise Huxtable wrote, "One simply walks through the beautiful doorway into another time and place in New York."

After the museum reopened in the 1980s, The Christian Science Monitor wrote that the surrounding industrial and commercial buildings "belie the fragile yet warm loveliness that waits inside the columned front door", particularly the ornate interiors. A Los Angeles Times reporter wrote of the house in 1988: "There are no curatorial flourishes here, no straining to re-create an era: You simply step inside and are whisked into another time and place." During the 1990s, the Toronto Star described the museum as "a touching and powerfully evocative document of the way a particular family of a particular class in a particular city lived at a particular point in the unrecoverable past", while American Heritage magazine wrote that the house had "the comfortable domestic elegance of another time". According to a 2021 review by Condé Nast Traveler, the Merchant's House Museum "is as close to a hidden gem as a New York City museum gets".

There has also been architectural commentary on the house itself. Before the museum opened, a New York Times reporter wrote that "the house was built in the finest traditions of the period", citing its main entrance and brick facade. Dorothy Draper of the New York Herald Tribune wrote in 1948 that the front door "stands out like a lady holding her starched skirts in the midst of a boiler factory", while the "perfect proportions of the large rooms with their high ceilings and heavy moldings" were the most notable part of the interior. According to Arthur Meeker of the Chicago Daily Tribune, the facade was "distinctly handsome", but the interior "has been sadly altered". Huxtable wrote that the AIA Guide to New York City had summarized "the importance of the Old Merchant's House in one bold-faced sentence: 'The original house is all there.'" Following the 1980s renovation, The Christian Science Monitor wrote that the double parlors had been called "two of the most beautiful rooms in America".

Landmark designations
Due to its architectural and historic importance, the Seabury Tredwell House has received several landmark designations. When the city's landmarks law was signed in April 1965, The Village Voice reported that the Seabury Tredwell House was "a likely candidate for salvation" under the law. The LPC designated the Seabury Tredwell House as one of the city's first 20 exterior landmarks in October 1965; The Wall Street Journal cites the house as Manhattan's first-ever designated city landmark. At a public hearing for the city-landmark designation, a curator for the Metropolitan Museum of Art described the house as "a unique, and I stress the word unique, survival in the City of New York". The building was designated as a National Historic Landmark in 1965, and it was added to the National Register of Historic Places on October 15, 1966, the day the National Historic Preservation Act of 1966 went into effect. The LPC designated the Seabury Tredwell House's basement, first floor, and second floor as an interior landmark in 1981.