The Allied Commission for Austria was established on July 5, 1945, as part of the U.S. Forces European Theater. The agency managed civil and military matters in Austria. On July 4, 1945, the Allied powers of the United States, Britain, France, and the Soviet Union established four-power occupation zones in Austria as a whole and in the city of Vienna as well. On July 27, 1955, the U.S. occupation of Austria ended as the State Treaty for the Re-establishment of an Independent and Democratic Austria took effect on May 15, 1955.
[Source: National Archives Online.]