On Monday, every player in Major League Baseball will wear Jackie Robinson’s No. 42 to honor the player who broke baseball’s color barrier on April 15, 1947. The country is also marking the centennial of Robinson’s birth on Jan. 31, 1919 throughout the year.

But the first African American to play regularly in the big leagues wasn’t the Brooklyn Dodgers second baseman, it was Moses Fleetwood “Fleet” Walker.

On May 1, 1884, the 26-year-old Walker was the catcher for the Toledo Blue Stockings in their opening game in the then-major league American Association. Six decades later, while Robinson was hailed as a pioneer, Walker was seen more as a curiosity.

Before a June game against the original Washington Nationals, The Washington Post noted that Toledo’s catcher “is a colored man, and no doubt many will attend the game to see our ‘colored brother’ in a new role.” After Toledo won, The Post reported that Walker played in “fine style” catching star pitcher Tony Mullane.

Like many of Walker’s white teammates, Mullane respected the barehanded catcher as a player but not as an equal. Walker “was the best catcher I ever worked with,” Mullane said years later, “but I disliked a Negro, and whenever I had to pitch to him I pitched anything I wanted without looking at his signals.”