The Basketball Association of America 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 regards as the first played in its history.^[4] 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 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 1948 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, however, NBL teams from Fort Wayne, Indianapolis, Minneapolis, and Rochester jumped to the BAA, which established the BAA as the league of choice for collegians looking to turn professional.^[5]Following the 1948-49 season, the BAA took in the remainder of the NBL: Syracuse, Anderson, Tri-Cities, Sheboygan, Denver, and Waterloo. In deference to the merger and to avoid possible legal complications, the league name was changed from the BAA to the National Basketball Association in spite of having the same BAA governing body including Podoloff.^[5]The new league had seventeen franchises located in a mix of large and small cities,^[7] as well as large arenas and smaller gymnasiums and armories. In 1950, the NBA consolidated to eleven franchises, a process that continued until 1953–54, when the league reached its smallest size of eight franchises, all of which are still in the league (the New York Knicks,Boston Celtics, Golden State Warriors, Los Angeles Lakers, Royals/Kings, Detroit Pistons, Atlanta Hawks, and Nationals/76ers). The process of contraction saw the league's smaller-city franchises move to larger cities. The Hawks shifted from the "Tri-Cities" (the area now known as the Quad Cities), to Milwaukee in 1951, and then to St. Louis, Missouri in 1955; the Royals from Rochester, New York to Cincinnati in 1957; and the Pistons from Fort Wayne, Indiana to Detroit in 1957.

Japanese-American Wataru Misaka broke the NBA color barrier in the 1947–48 season when he played for the New York Knicks. 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.^[8][9] Hunter was cut from the team during training camp,^[8][10] 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 theWashington Capitols. During this period, the Minneapolis Lakers, led by center George Mikan, won five NBA Championships and established themselves as the league's firstdynasty.^[11] To encourage shooting and discourage stalling, the league introduced the 24-second shot clock in 1954.^[12] If a team does not attempt to score a field goal (or the ball fails to make contact with the rim) within 24 seconds of obtaining the ball, play is stopped and the ball given to its opponent.