On this day in 1947, Jackie Robinson, age 28, becomes the first African-American player in Major League Baseball when he steps onto Ebbets Field in Brooklyn to compete for the Brooklyn Dodgers against the Boston Braves. Robinson broke the color barrier in a sport that had been segregated for more than 50 years.
Exactly 50 years later, on April 15, 1997, Robinson’s groundbreaking career was honored and his uniform number, 42, was retired from Major League Baseball by Commissioner Bud Selig in a ceremony attended by over 50,000 fans at New York City’s Shea Stadium.
Robinson’s was the first-ever number retired by all teams in the league.
Source: Jackie Robinson breaks color barrier – Apr 15, 1947 – HISTORY.com
The History of the Atlanta Braves 