The National Basketball League (NBL) was one of the oldest professional basketball leagues created in the United States. Originally established in 1935 during what was considered to be the height of the Great Depression as the Midwest Basketball Conference, it changed its name to the NBL on October 6, 1937, weeks before it was set to begin what was to have been its third season of play under that name, effectively becoming a proper professional league in the process. Before the NBL was created, the best basketball teams were created as barnstorming operations like the former ABL Original Celtics team, the New York Renaissance, the Harlem Globetrotters, and the Philadelphia Sphas (the last of whom also played in the original rivaling American Basketball League as well after previously being of the Eastern Basketball League). After the 1948–49 season, its twelfth and final season of existence under that name, it ended up merging operations with the more newly established Basketball Association of America (BAA) to form the National Basketball Association (NBA) to hold many of the best professional basketball teams for the modern-day era, with the BAA being considered both the official recordholders and the starting point of the NBA over the longer-lasting NBL (despite its longer starting point), with few recognitions from the NBL's days being properly recognized by the NBA in the present day. Five current NBA teams trace their history back to the NBL: the Atlanta Hawks (formerly the Buffalo Bisons/Tri-Cities Blackhawks), the Detroit Pistons (formerly the Fort Wayne Zollner Pistons), the Los Angeles Lakers (formerly the Detroit Gems/Minneapolis Lakers), the Philadelphia 76ers (formerly the Syracuse Nationals), and the Sacramento Kings (formerly the Rochester Royals, though their earliest history went as far back as 1923 by the days of the Rochester Seagrams), with five former BAA/NBA teams also tracing their roots to the NBL in the Indianapolis Jets (formerly the Indianapolis Kautskys), the Anderson Packers (formerly the Anderson Duffey Packers), the original Denver Nuggets (not to be confused with the current Denver Nuggets NBA team that exists from the former Denver Rockets ABA team), the Sheboygan Red Skins, and the Waterloo Hawks, as well as one more team that was originally meant to be an NBL expansion team later joining the NBA as an expansion team instead in the Indianapolis Olympians. Another NBL team that is still active, albeit not as a professional team, is the Akron Goodyear Wingfoots, who left the NBL during World War II to become a National Industrial Basketball League team before becoming an Amateur Athletic Union Elite club.
As of 2025, despite merging with the BAA to form the NBA, the NBA ended up adopting the BAA's history and records instead of the NBL's history up until at least 1946, if not alongside the BAA's history up until 1949 due to the BAA being considered a more prestigious professional basketball league at the time due to them having the teams that played in larger, more prestigious venues and cities than the NBL did. As a result of this decision, the NBA does not recognize the NBL's history and records in its own record books, similar to how the NBA doesn't recognize much of the history of the American Basketball Association, which it also merged with in 1976, nor its own records as well.
