The National Basketball Association (NBA) is a professional men's basketball league, consisting of 30 teams in North America (29 in the United States and one in Canada). The NBA was founded in New York City on June 6, 1946, as the Basketball Association of America (BAA). It adopted the name National Basketball Association at the start of the 1949–50 season when it absorbed the National Basketball League (NBL). The NBA is an active member of USA Basketball, which is recognized by the International Basketball Federation (FIBA) as the National Governing Body (NGB) for basketball in the country. The league is considered to be one of the four major professional sports leagues of North America.
There have been 15 defunct NBA franchises. The Anderson Packers, the original Denver Nuggets, the Indianapolis Jets, the Sheboygan Red Skins, and the Waterloo Hawks had played in the NBL before joining the NBA, while the original Baltimore Bullets had played in the American Basketball League before joining the NBA. Nine of the fifteen defunct teams have played in only one NBA season. The Packers, Red Skins, and Hawks left the NBA for the National Professional Basketball League, and are the only defunct teams to have ceased to exist in a league other than the NBA. The original Bullets were the last defunct team to leave the NBA, having left during the 1954–55 season, and are the only defunct team to have won an NBA championship. The Chicago Stags, the Indianapolis Olympians, the Cleveland Rebels, the Packers, and the Red Skins qualified for the playoffs in every year they were active in the league. Among cities that have hosted defunct NBA franchises, Chicago, Cleveland, Denver, Detroit, Indianapolis, Toronto, and Washington, D.C. are the only ones to currently have an NBA team, although Providence, Rhode Island, Anderson, Indiana and Sheboygan, Wisconsin are around an hour from a market with an NBA franchise.