When he retired at the end of the 1956 season, three major league teams had yet to integrate their clubhouses. The Philadelphia Phillies integrated in 1957 with John Kennedy, the Detroit Tigers integrated in 1958 with Ozzie Virgil, and the Boston Red Sox were the last major league team to integrate when they signed Pumpsie Green in 1959. (AP Photo)

Today, April 15, the legacy of Jackie Robinson, the first African-American player to integrate the national pastime in the 20th century, is being commemorated by Major League Baseball.

To celebrate the occasion theGrio put together a list of 10 things you may not know about Jackie Robinson.

Every Major League Baseball player will don Robinson’s number, 42, marking the 67th anniversary of the Hall of Famer breaking baseball’s color barrier.

Families of both Robinson and the late Nelson Mandela will be at Yankee Stadium today paying tribute to the legend.

Click through the slideshow to see some of the lesser known facts about Robinson.

Follow Carrie Healey on Twitter @CarrieHeals