The 1939 airport was developed by the city as a municipal airport. In 1939 two three-thousand-foot (910 m) runways were built, and a hangar east of the runway intersection. During World War II the federal government established an Army Air Forces base at Rosecrans with numerous improvements being made in 1942 and 1943. The diagonal runways were doubled in length and a north-south runway was built, along with an aircraft parking apron and many temporary buildings, including Hangar T-1020. In 1948 much of the airfield's facilities were conveyed to the city, except for set aside for use by the Air National Guard. Airport construction during this period consisted of pump house buildings and T-hangars (1949–50) and a terminal and administration building (1951–52).