The United States Swimming National Championships (a.k.a. "Nationals") are held annually, in summer. The event is organized by USA Swimming, and is held in a long course (50m) pool. In the past, and as recently as 2007, there were 2 meets annually: and Spring and Summer Nationals. The Spring meet began as a 25-yard (short course) meet, while the Summer meet was long course. Prior to USA Swimming's creation in the late 1970s, the meet was run by the AAU.