Jackie Robinson Day: 4 Facts About His Jersey No. 42, Now Retired in MLB

April 15 will be forever known as Jackie Robinson Day in Major League Baseball.

Since its inception in 2007, Jackie Robinson Day has been held in high esteem in the baseball world. It's the day that the country acknowledges No. 42, Jackie Robinson. Jackie was the man who broke MLB's "color barrier" and helped to pave the way for racial equality in the United States.

In honor of Jackie Robinson Day, here are four facts about the famous number and its ties to the man himself.

Jackie Robinson Wore Other Numbers Before 42

No. 42 is one of the most iconic numbers in all of sports. However, it wasn't the only number Robinson wore in his life.

According to The New York Times, Robinson wore a slew of different numbers in various sports before his debut with the Brooklyn Dodgers in 1947.

While playing football for UCLA, Robinson wore 28 and wore the No. 18 when playing basketball for the program.

When he played for the Kansas City Monarchs in the Negro Leagues, he wore as many as three different numbers. According to various accounts, Robinson may have worn Nos. 5, 8 and 23.

During Robinson's time with the Montreal Royals, the Dodgers' top farm team, there are accounts that saw Robinson wear No. 10.

So why did Jackie Robinson wear 42 with the Brooklyn Dodgers? There's no concrete answer, and it seems to be just a matter of the organization assigning him that number.

It's an interesting footnote considering how players today are keen on having a specific number, whether it's the number they wore in high school or college, etc., but when the number was assigned to Jackie, no one seemed to realize the significance it would have to the sport.

Ken Griffey Jr. Is Responsible for Everyone Wearing 42 on Jackie Robinson Day

Every Jackie Robinson Day, MLB players, coaches and managers wear No. 42 to honor the man.

This wasn't always the case, though, and Hall of Fame outfielder Ken Griffey Jr. actually began the trend of wearing the iconic number on the special day.

When then–MLB Commissioner Bud Selig retired No. 42 on April 15, 1997—50 years after Robinson's MLB debut—Griffey, who was with the Seattle Mariners at the time, asked that his uniform number be flipped from 24 to 42.

Ten years later, on the 60th anniversary of Robinson's major league debut, Griffey, then with the Cincinnati Reds, asked Selig if he could wear 42 again for the special occasion.

"I said, 'Would it be possible if I wore 42 on Jackie Robinson Day?'" Griffey recalled during an interview with Harold Reynolds on MLB Network. "We had a 10-minute conversation. [Selig] said, 'Is it OK if I call Rachel [Robinson, Jackie's wife] and ask if it's OK?'"

Selig would call Griffey back the next day and the request was granted, but he told the outfielder that he would offer the same request to other players, which the future Hall of Famer was happy to share.

That year, Griffey and other African American players wore No. 42 on Jackie Robinson Day. For the next two seasons, players had the option to wear the number on April 15.

In 2009, Selig expanded the practice to have every player, coach and manager wear No. 42 on Jackie Robinson Day, a tradition that continues to this day.

Last Player to Wear 42

When former MLB Commissioner Bud Selig retired No. 42 from baseball in 1997, players that were currently wearing the number would be the last to ever wear them.

As the years went by the number of players wearing 42 would dwindle until there was only one left. New York Yankees closer Mariano Rivera, who debuted with the team in 1995 and retired in 2013 would be the last player to ever wear No. 42.

Rivera recently revealed to Mark Feinsand of MLB.com that he initially was given No. 58 by the Yankees, but never appeared in a game wearing it. He would be given No. 42 soon after and would wear it for over 1,000 games with the Yankees.

"I wanted to make Mr. Jackie Robinson proud of the legacy that he left us," Rivera said. "Me, being the last No. 42, doing it in a great arena as New York, I was thankful for the legacy he left for us to continue and pushing it forward, passing it down to the next generation."

No. 42 Was Retired Twice After Jackie

Retiring numbers in professional sports is a common practice to celebrate the individual achievements of players to their team.

When Jackie's No. 42 was retired across MLB in 1997, a couple of teams honored other players in the years after the mandate.

The New York Yankees retired Mariano Rivera's 42 in 2013. Rivera is the greatest closer of all-time and helped the Bronx Bombers capture five World Series victories.

The St. Louis Cardinals retired Bruce Sutter's No. 42 in 2006. Sutter was a dominant reliever in the '70s and '80s for the Chicago Cubs, Cardinals and Atlanta Braves before retiring in 1989. For St. Louis, he helped the team win the 1982 World Series and was inducted into the Baseball Hall of Fame in 2006.

Jackie Robinson
Jackie Robinson of the Brooklyn Dodgers at bat during a game, 1940s or 1950s. His No. 42 has been retired across Major League Baseball. Robert Riger/Getty