The United States Army Transport Service (ATS) was established as a sea-going transport service that was independent of the Navy Department. ATS operated army transport ships for both troop transport and cargo service between United States ports and overseas posts. This service is often confused with the Army Transportation Service, created in France in 1917 to manage American Expeditionary Forces transport. ATS was a branch of the Quartermaster Corps responsible for land and water transport, becoming a separate United States Army Transportation Corps on July 31, 1942.