The growing popularity of roller skating in the United States led to the formation of organized multi-day endurance races for cash prizes as early as the mid-1880s. Speed and endurance races continued to be held on both flat and banked tracks in the century's first three decades and spectators enjoyed the spills and falls of the skaters. The term "roller derby" was used to refer to such races by 1922.
There are a multitude of roller derby associations in the United States.
Due to historical accident, the term "league" in modern roller derby means something more akin to a football club than to a traditional sports league thus, there are a very large number of leagues sometimes even including two or more based in a single city.