Wounded Marine lying on a stretcher in a trench is being treated for a head wound, Toul sector. Toul was also the primary base of the Air Service, United States Army, a predecessor organization of the United States Air Force during World War I. It was a base for many of the 45 wartime squadrons including the squadrons of the 1st Pursuit Group, 1st Observation Group and others. The Americans referred to the area around Toul as the Toul Sector. Two large operations were launched from this area: the St. Mihiel offensive and the Meuse-Argonne offensive, both in September. March 22, 1918 U.S. Signal Corps photo.