In May 1942, the War Department considered the creation of a Services of Supply (SOS) organization in the European Theater of Operations (ETO) to handle the large volume of service troops and supplies being deployed to the United Kingdom for Operation Bolero, the buildup of US troops there for Operation Sledgehammer, the proposed Allied invasion of France in 1942, and Operation Roundup, the larger follow up operation in 1943. Lee's name was put forward for the position of its commander by the Secretary of War, Stimson; the commander of United States Army Services of Supply (USASOS), Lieutenant General Brehon B. Somervell; and McNair, the commander of Army Ground Forces. Marshall had already formed a positive impression of Lee when he had commanded the Pacific Ports of Embarkation, and decided to appoint him.