National Basketball Association
Creation and BAA–NBL merger (1946–1956)

The NBA traces its roots to the Basketball Association of America which was founded in 1946 by owners of the major ice hockey arenas in the Northeastern and Midwestern United States and Canada. On November 1, 1946, in Toronto, Ontario, Canada, the Toronto Huskies hosted the New York Knickerbockers at Maple Leaf Gardens, in a game the NBA now refers to as the first game played in NBA history. The first basket was made by Ossie Schectman of the Knickerbockers.

Although there had been earlier attempts at professional basketball leagues, including the American Basketball League (ABL) and the NBL, the BAA was the first league to attempt to play primarily in large arenas in major cities. During its early years, the quality of play in the BAA was not significantly better than in competing leagues or among leading independent clubs such as the Harlem Globetrotters. For instance, the 1947 ABL finalist Baltimore Bullets moved to the BAA and won that league's 1948 title, and the 1948 NBL champion Minneapolis Lakers won the 1949 BAA title.

Prior to the 1948–49 season, the BAA lured away the Fort Wayne Pistons, Indianapolis Kautskys, Minneapolis Lakers, and Rochester Royals from the NBL with the prospect of playing in major venues such as Boston Garden and Madison Square Garden. The NBL hit back by outbidding the BAA for the services of several players, including Al Cervi, rookie Dolph Schayes and five stars from the University of Kentucky while also gaining the upper hand in Indianapolis with the creation of the Indianapolis Olympians while the Kautskys folded. With several teams facing financial difficulties, the BAA and the NBL agreed on a merger on August 3, 1949, to create the National Basketball Association. Maurice Podoloff, the president of BAA, became the president of the NBA while Ike Duffey, president of the NBL, became the chairman. The NBA later adopted the BAA's history and statistics as its own but did not do the same for NBL records and statistics.

The new league had seventeen franchises located in a mix of large and small cities, as well as large arenas and smaller gymnasiums and armories. In 1950, the NBA consolidated to eleven franchises, a process that continued until 1954–55, when the league reached its smallest size of eight franchises: the New York Knicks, Boston Celtics, Philadelphia Warriors, Minneapolis Lakers, Rochester Royals, Fort Wayne Pistons, Milwaukee Hawks, and Syracuse Nationals, all of which remain in the league today, although the latter six all did eventually relocate. The process of contraction saw the league's smaller-city franchises move to larger cities. The Hawks had shifted from the Tri-Cities to Milwaukee in 1951, and later shifted to St. Louis in 1955. In 1957, the Rochester Royals moved from Rochester, New York, to Cincinnati and the Pistons moved from Fort Wayne, Indiana, to Detroit.

Japanese-American Wataru Misaka is considered to have broken the NBA color barrier in the 1947–48 season when he played for the New York Knicks in the BAA. He remained the only non-white player in league history prior to the first African-American, Harold Hunter, signing with the Washington Capitols in 1950. Hunter was cut from the team during training camp, but several African-American players did play in the league later that year, including Chuck Cooper with the Celtics, Nathaniel "Sweetwater" Clifton with the Knicks, and Earl Lloyd with the Washington Capitols. During this period, the Minneapolis Lakers won five NBA championships and established themselves as the league's first dynasty; their squad was led by center George Mikan who was the NBA's first superstar. To encourage shooting and discourage stalling, the league introduced the 24-second shot clock in 1954.
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