Nat “Sweetwater” Clifton, Number 8, joined the New York Knicks in 1950 as the National Basketball Association began to accept black players. (Ed Ford/AP)

As we get ready for Sunday’s National Basketball Association All-Star Game, featuring such superstars as LeBron James and Stephen Curry, it’s hard to believe that the league had no black players during its first few years.

That’s right. The NBA, where today nearly 75 percent of the players are black, originally had no black players. Zero. It’s a complicated piece of sports history, so let’s take a look.

The Basketball Association of America, later renamed the NBA, started in 1946. The founders of the league were mostly owners of arenas who wanted another sport to fill their buildings. In the 1940s, professional basketball was not as popular as baseball, boxing or college basketball.

Eleven teams and more than 150 players played in that first season, but none of them was black. It was the same for the next three NBA seasons.

That was not surprising, because much of America back then was segregated. Black people were not allowed to go to the same schools or public places or hold many of the same jobs as white people. It was not right, but that was the way it was.

Although black men did not play in the NBA, they did play basketball. Some played in smaller pro and semipro leagues scattered around the country. The best of them played on such famous all-black teams as the New York Renaissance (also called the Rens) and the Harlem Globetrotters.

The Rens and the Globetrotters were good. The Rens won the first World Professional Basketball Tournament in Chicago in 1939. The Globetrotters won the same tournament in 1940.

The Globetrotters traveled around the country beating all sorts of teams, including the NBA champion Minneapolis Lakers. They defeated most teams so easily that they started including trick passes and shots near the end of the games to keep things entertaining.

The Globetrotters were so popular that NBA owners held doubleheaders, or two games on the same night. Two NBA teams played in the first game, and the Globetrotters played in a second, featured game.

The NBA owners and their arenas made a lot of money from the Globetrotters games. The owners did not want to make Globetrotters owner Abe Saperstein angry by hiring black players who might play for Saperstein’s team.

Finally, the owner of the New York Knicks said he wanted to sign Globetrotter Nat “Sweetwater” Clifton to an NBA contract. At first, the other owners refused to allow it. But in 1950, they changed their minds after the Knicks threatened to leave the league.

Syracuse’s Earl Lloyd, Number 11, goes up against Fort Wayne’s Mel Hutchins during a 1955 NBA basketball game in Indianapolis, Indiana. Lloyd was the first black player to play in an NBA game, when he was on the Washington Capitols in 1950. Chuck Cooper and Nat “Sweetwater” Clifton, also African Americans, played that season, too. (AP)

That same year, the Boston Celtics drafted Chuck Cooper. The Washington Capitols (not the hockey Capitals) chose Earl Lloyd, who grew up in Alexandria, Virginia. Black players were finally in the NBA.

Clifton, Cooper and Lloyd went on to have solid NBA careers. (Clifton played in the 1957 All-Star Game.) They had to deal with many of the prejudices of their time, but they paved the way for Michael Jordan, Kobe Bryant and so many other great black players.

Bowen writes the sports opinion column for KidsPost. He is the author of 21 sports books for kids. His next basketball book — “Outside Shot” — will be published in March.