Prior to 1947 professional baseball was segregated, and blacks played in their own Negro leagues, called Negro Leagues Baseball. These leagues provided the only opportunities for several generations of extremely talented and dedicated minority ball players. Professional Negro baseball leagues were organized to showcase the talents of African-American players during segregation. Their organized efforts became a successful business enterprise generating millions of dollars in revenue and thousands of jobs for other blacks besides players, coaches, managers, and team owners. Andrew “Rube” Foster, a player, manager, and owner with the Chicago American Giants, developed the Negro National League in 1920 in Kansas City, Missouri. Similar efforts in southern and eastern regions produced the Southern Negro League, Eastern Colored League, East-West League, and other organizations, but the Negro National League (1920–1931; 1933–1948) and the Negro American League (1937–1960) had the most sustained success.

During the heyday of the Negro Leagues, their best teams included the Kansas City Monarchs and the Homestead Grays, with legendary players such as pitcher Leroy “Satchel” Paige and home run hitter Josh Gibson. Their all-star games sold out major league venues in Chicago, and the best black players outclassed white major league teams in unofficial exhibition games. Gibson was a strong, stoic catcher and was called “the best black baseball player white America did not see.” Kansas City Monarch Buck O’Neil (1911–2006) became a folk hero as a character in Ken Burns’s PBS documentary Baseball, which aired in the late 1990s. When Brooklyn Dodgers owner Branch Rickey broke the color line by signing Jackie Robinson from the Monarchs in 1945, his integration of the major leagues in 1947 ironically signaled the demise of the Negro Leagues. By 1960 top young black players such as Henry “Hank” Aaron and Willie Mays were part of major league teams. Many of the earlier players are now honored in both the Baseball Hall of Fame in Cooperstown, New York, and the Negro Leagues Baseball Museum in Kansas City.