August 3rd 1949: The creation of the modern NBA
The National Basketball League (NBL) merged with the Basketball Association of America (BAA) to form what is now the National Basketball Association (NBA). The NBL originally formed in 1937 and consisted of nearly 38 teams. The BAA consisted of 16 teams and formed in 1946.
Since the formation of the BAA, there was competition amongst leagues for both teams and players. One of the more notable players included George Mikan, who ended up playing in both leagues at different times. Unlike the NBL, the BAA was unique in that it presented an opportunity to play in larger arenas, including both the Boston Garden & Madison Square Garden. Coincidentally, the initial BAA franchises included the current day Boston Celtics & New York Knicks.
Due to cannibalized competition, both leagues met in New York City to finalize a merger. Many of the teams in the NBL folded or merged with existing teams in the BAA or NBL. Interestingly, 5 of the current teams in the NBA can directly trace their roots back to the NBL. For example, the Minneapolis Lakers migrated to the NBA from the NBL. The Lakers eventually moved to Los Angeles in 1958 and are well known as the Los Angeles Lakers. The Rochester Royals of the NBL are now known as the Sacramento Kings.