This post hospital was organized as part of the Fort Hospitals of the Defenses of Washington by Brigadier General James S. Wadsworth.
Fort Saratoga Post Hospital served the 1st Brigade until the 1st Brigade forts were redefined as 2nd Brigade forts in July, 1864. The 1st, then 2nd, Brigade consisted of the following forts, garrisons and redoubts: Saratoga (head quarters), Thayer, Lincoln, Jamison, Bunker Hill, Slemmer, Stevens, Slocum, Totten.
The hospital was located outside of Fort Saratoga, near Chapel Spring, on the Bladenburg road between Forts Thayer and Bunker Hill. In addition to the forts listed, it served the following garrisons: from June 1862 to March 1864, the 2nd PA heavy artillery (112 volunteers); from Nov. 1862 to March 1863, the 3rd Maine battalion.