How did Moses Fleetwood Walker make baseball history with the Toledo team?

Moses Fleetwood "Fleet" Walker made baseball history in 1884 when he became one of the first two African Americans to play in a recognized major league, the American Association, as a catcher for the Toledo, Ohio, team.12

While the first professional baseball league formed in the 1870s did not have a written rule barring Black players, it was tacitly understood that they were not welcome. Despite this, Walker and his brother, Welday Walker, broke this barrier by appearing on the roster for Toledo in 1884. This achievement occurred during a period when the color line in professional baseball was not yet consistently enforced, allowing a number of Black players to participate in minor and major league teams before a "gentlemen’s agreement" to exclude them eventually prevailed in the late 19th century.2