The United States Swimming National Championships 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: a Spring and a Summer Nationals. The Spring meet began as a 25-yard 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.