April 23, 1924
Chuck Harmon became the first African American to appear in a game for the Reds when he pinch hit for Corky Valentine on April 17, 1954. In the same game, Nino Escalera also debuted for the Reds; Esccalera was also black, but was Puerto Rican, not African American. Harmon was an excellent athlete, and also tried out for the Boston Celtics when the NBA was integrated for the 1950-51 season. After failing to make the Celtics, Harmon finished the season as a player-coach for Utica of the American Basketball League. According to Wikipedia, that made him one of the first (and possibly the first) African Americans to coach an integrated professional basketball team.
April 23, 1967
Rheal Cormier wrapped up his 16-year career pitching for the Reds. In 2006 and 2007, Cormier pitched 27 games in relief with a 5.29 ERA.
April 22, 1910
Lew Riggs was a member of the 1940 World Champion Cincinnati Reds, though his time was limited to only 41 games that season. In 1936, Riggs was a National League All-Star.
April 22, 1933
Bob Schmidt spent just a part of the 1961 season with the Reds; he was traded in December that year to the Senators, giving Topps plenty of time to reflect the change on his 1962 card. Schmidt is pictured with the Reds on a 1962 Salada coin and in the 1980 TCMA 1961 Reds set, neither of which I own.
April 22, 1959
Is Terry Francona a future Hall of Famer? While his playing record is far from Hall-worthy, he boasts quite a resume as a manager. Francona twice led the Boston Red Sox to World Championships, and last year his Indians narrowly lost the Series to the Cubs. He was named Manager of the Year in 2013 and again in 2016, and has seven other top six finishes for the award. He will need to put together several more winning seasons to get his win total up, though, and he has expressed some concerns about his health.
April 21, 1977
Kip Wells was considered a prospect early in his career, but never really lived up to that promise. He twice led the National League in losses, and his career record was 69-103. He pitched in 10 games for the Reds in 2009, going 2-3 with a 4.66 ERA.
April 21, 1980
Jeff Keppinger made a lot of contact during his career, striking out only 214 times in 2882 at bats. He twice led the NL in at bats per strikeout. In 2008 with the Reds, Keppinger struck out only once every 19.1 at bats. He also played for the Mets, Royals, Astros, Giants, Rays, and White Sox.