Until 1943, the air base in Townsville was a joint operation between the Australians and the Americans. In June of that year, control was handed over to the Americans alone, and remained that way until early 1945. The threat of Japanese invasion, however, had receded by late 1942, after the Battles of the Coral Sea and Midway. The air force base at Townsville, and the operations building at Green Street, lessened in importance as wartime operations moved north and Townsville's air bases became large workshop areas in the later years of the war. There are few records regarding the Green Street site and the operations building at the time of the war's end. A request however, was made to the Department of the Interior in June 1947 to officially acquire the Green Street site. The Commonwealth acquired title to the site in 1951. The RAAF base in Townsville was always considered a permanent base, and after the war the base was reduced in size to that originally planned before the war.