In the opening months of World War I, replacement troops for battle-depleted German infantry units were drawn from lesser-trained Ersatz Corps, who were less effective than the troops they replaced.
United States Marine Corps | United States Army Corps of Engineers | Peace Corps | Royal Flying Corps | United States Army Air Corps | Royal Army Medical Corps | Civilian Conservation Corps | Army Air Corps | Corps of Engineers | Reserve Officers' Training Corps | Marine Corps Recruit Depot Parris Island | Commandant of the Marine Corps | Royal Army Service Corps | Royal Army Ordnance Corps | Marine Corps Base Quantico | Royal Armoured Corps | Judge Advocate General's Corps | Corps | Air Training Corps | Marine Corps Recruit Depot San Diego | Marine Corps Base Camp Lejeune | King's Royal Rifle Corps | Medical Service Corps | Marine Corps Base Hawaii | Australian and New Zealand Army Corps | Army Air Corps (United Kingdom) | Second Corps | Royal Corps of Signals | Ordnance Corps (United States Army) | German Student Corps |