By 1863, regional evacuation depots were established to process the large number of casualties. As with the division and Corps hospital systems, one medical officer would command the depot and several subordinate medical officers were delegated management of key departments within the organization such as food and shelter, Military administration, and supply replenishment. Each depot was organized into Corps hospitals consisting of Division hospitals.
In 1864, the City Point Depot merged the five army corps of the Army of the Potomac effectively caring for 6,000 to 10,000 patients. The hospital wards consisted of log buildings, called pavilions, of approximately 20 feet wide by 50 feet long. The hospital eventually grew to 90 pavilions and 324 additional tents. It was outfitted with iron beds, steam water pumps, and a steam laundry operated by former slaves. Mosquito nets for the beds defended against the swarms of flies drawn by the open latrines. Each Corps hospital operated its own dispensary, commissary store house, and general and special diet kitchens. Wounded soldiers would either convalesce there then return to their regiments or be evacuated to one of the many general hospitals established throughout the north.