Battle of Williamsburg order of battle: Union

The following United States Army units and commanders fought in the Battle of Williamsburg of the American Civil War. The Confederate order of battle is shown separately.

Military rank

 * MG = Major General
 * BG = Brigadier General
 * Col = Colonel
 * Ltc = Lieutenant Colonel
 * Maj = Major
 * Cpt = Captain
 * Lt = Lieutenant
 * Bvt = Brevet

Other

 * w = wounded
 * mw = mortally wounded
 * k = killed

Army of the Potomac
MG George B. McClellan Commanding in the field: BG Edwin V. Sumner

III Corps
BG Samuel P. Heintzelman

IV Corps
BG Erasmus D. Keyes

Cavalry Advanced Guard
BG George Stoneman