Baseball color barrier

The color line in American baseball excluded players of Black African descent from Major League Baseball and its affiliated Minor Leagues until 1947 (with a few notable exceptions in the 19th century before the line was firmly established). Racial segregation in professional baseball was sometimes called a gentlemen's agreement, meaning a tacit understanding, as there was no written policy at the highest level of organized baseball, the major leagues. But a high minor league's vote in 1887 against allowing new contracts with black players within its league sent a powerful signal that eventually led to the disappearance of blacks from the sport's other minor leagues later that century, including the low minors.

After the line was in virtually full effect in the early 20th century, many black baseball clubs were established, especially during the 1920s to 1940s when there were several Negro Leagues. During this period some light-skinned Hispanic players, Native Americans, and native Hawaiians were able to play in the Major Leagues.

The color line was broken for good when Jackie Robinson signed with the Brooklyn Dodgers organization for the 1946 season. In 1947, both Robinson in the National League and Larry Doby with the American League's Cleveland Indians appeared in games for their teams. By the late 1950s, the percentage of black players on Major League teams matched or exceeded that of the general population.

Formal beginning of segregation followed the baseball season of 1867. On October 16, the Pennsylvania State Convention of Baseball in Harrisburg denied admission to the "colored" Pythian Baseball Club.

...
Wikipedia