Roller derby in the United States

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.

[1][2][3] Speed and endurance races continued to be held on both flat and banked tracks in the century's first three decades[4] and spectators enjoyed the spills and falls of the skaters.

[5][6] The term "roller derby" was used to refer to such races by 1922.

[7] There are a multitude of roller derby associations in the United States.

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.