1804–05 United States House of Representatives elections

The 1804–05 United States House of Representatives elections were held on various dates in various states between April 24, 1804 (in New York) and August 5, 1805 (in Tennessee). Each state set its own date for its elections to the House of Representatives before the first session of the 9th United States Congress convened on December 2, 1805. The elections occurred at the same time as President Thomas Jefferson's re-election. Elections were held for all 142 seats, representing 17 states.

Under Jefferson's popular administration, his party continued to gain seats in the House. Territorial acquisitions from the Louisiana Purchase and economic expansion gave voters a positive view of the Democratic-Republicans, whose majority, already commanding in the 8th Congress, now surpassed three-quarters of the total membership. Following this election, Federalists were able to secure few seats outside of New England and party legitimacy deteriorated as political thought turned away from Federalist ideals perceived to be elitist and anti-democratic.

Special elections
There were special elections in 1804 and 1805 during the 8th United States Congress and 9th United States Congress.

Elections are sorted here by date then district.

Indiana Territory
See Non-voting delegates, below.

Massachusetts
The majority requirement was met in all 17 districts in the 1804 elections.

Mississippi Territory
See Non-voting delegates, below.

New Jersey
The Federalist ticket was announced only a week before the election, with no active campaigning.

New York
New York held elections for the 9th Congress on April 24–26, 1804. For this year and the next election year, the 2nd and 3rd districts had combined returns, effectively a plural district with 2 seats, though still numbered as separate districts. At the time, District 2 consisted of only part of New York County, while District 3 consisted of the remainder of New York County plus Kings and Richmond Counties. By consolidating the two, it ensured that New York County would be combined into a single district.

Tennessee
Beginning with the 9th Congress, Tennessee was divided into 3 districts.

Vermont
Vermont required a majority for election, which frequently mandated runoff elections. The VT's 2nd congressional district, and VT's 3rd congressional district districts both required second elections in this election cycle, and districts both required second elections in this election cyclethe 3rd district required a third election.

Non-voting delegates
There were three territories with non-voting delegates in the 9th Congress, one of which (the Orleans Territory) did not send its first representative until 1806. The delegates were elected by the territorial legislatures, votes here are the number of members of the territorial legislatures voting for each candidate.

In the Mississippi Territory, the territorial legislature was locked. The first vote given above was on the 7th ballot, after which point the territorial legislature adjourned, the second vote was at a later session of the territorial legislature.

! Indiana Territory At-large
 * colspan=3 | None (District created)
 * | New delegate elected September 11, 1805. Federalist gain. New delegate was seated December 12, 1805.
 * nowrap | First ballot:

Benjamin Parke (Federalist) 5

Thomas J. Davis (Unknown) 5

Jesse B. Thomas (Democratic-Republican) 1 Second ballot:

Benjamin Parke (Federalist) 5

Thomas J. Davis (Unknown) 5

Shadrach Bond (Unknown) 1 Third ballot:

✅ Benjamin Parke (Federalist) 7

Thomas J. Davis (Unknown) 4

! Mississippi Territory At-large
 * William Lattimore
 * | Democratic-Republican
 * 1803
 * Incumbent re-elected on an unknown date in 1805.
 * nowrap | Seventh ballot:

William Lattimore (Democratic-Republican) 5

Cato West (Unknown) 5

William Gordon Freeman (Unknown) 4 Eventual decision:

✅ William Lattimore (Democratic-Republican) 10

Cato West (Unknown) 2

John Ellis (Unknown) 1


 * }