SportBusiness.com

The Arena Football League (AFL) was founded in 1987 as an American football indoor league by Jim Foster. It is played indoors on a smaller field than American football, resulting in a faster and higher-scoring game. The sport was invented in 1986, and patented, in 1990 by Foster, a former executive of the United States Football League and the National Football League. Nearly two months after the New Orleans Voodoo folded on the league's owners chose to cancel the 2009 season to work on developing a long-term plan to improve its economic model.

Four months after the league canceled its 2009 season for a lack of funding, the nine-year-old Los Angeles Avengers folded, leaving the league with 15 teams. [source]