John Jordan "Buck" O'Neil had a great career as a standout first baseman, then manager with the Negro Leagues' Kansas City Monarchs in the late 1930s through the mid 1950s.
After his former Negro League team was sold, he was hired by the Cubs as a scout, having a hand in discovering Billy Williams and signing Lou Brock among others. O'Neil served as an unofficial coach for a while until 50 years ago today, the Cubs officially hired him as the first African-American coach in Major League Baseball history.
Unfortunately, he never got a chance to manage; he came right at the time the Cubs were experimenting with the ridiculous "College of Coaches," and O'Neil in his autobiography "I Was Right On Time" identifies then-Cubs executive Charlie Grimm as the one who made the call to exclude him from the rotation.
O'Neil eventually returned to the scouting ranks, and later became the star of Ken Burns' "Baseball" documentary, bringing the Negro Leagues back to life with his captivating description.
O'Neil was the chairman of the Negro Leagues Baseball Museum in Kansas City, and shortly before his death at age 94 in October 2006, became the oldest man to play a professional baseball game, drawing two intentional walks in the July 18, 2006 Northern League All-Star Game.
He was truly one of baseball's all-time great ambassadors.