### Instruction:
Write some important points about the National Basketball League from the given text

### Input:
The National Basketball League (NBL) was a professional basketball league in the United States established in 1937. After the 1948–49 season, its twelfth, it merged with the Basketball Association of America (BAA) to create the National Basketball Association (NBA). Five current NBA teams trace their history back to the NBL: the Atlanta Hawks, the Detroit Pistons, the Los Angeles Lakers, the Philadelphia 76ers, and the Sacramento Kings.

### Response:
1. In the United States, a professional basketball league called the National Basketball League (NBL) was founded in 1937.
2. It united with the Basketball Association of America (BAA) to become the National Basketball Association after its twelfth season, 1948–1949 (NBA).
3. The Atlanta Hawks, Detroit Pistons, Los Angeles Lakers, Philadelphia 76ers, and Sacramento Kings are five current NBA teams whose roots can be traced to the NBL.