 However, the demands of war meant that the 2nd Wisconsin Regiment was needed for the Peninsula Campaign and left Fort Corcoran in late 1861.Throughout the war, Fort Corcoran's rear location and proximity to the supply depots of Washington meant that a steady stream of Union regiments rotated through the fort and the military camps nearby for much of the war.In August 1861 alone, regiments from Maine, Massachusetts, New York, Michigan, Rhode Island, Wisconsin, and Pennsylvania served in or near the fort.