What is Jackie Robinson Day? Explaining why every MLB team wears 42

Major League Baseball celebrates something special today.

April 15 marks Jackie Robinson Day, and each year the league commemorates the legacy of Brooklyn Dodgers star and Hall-of-Famer Jackie Robinson.

Each year on this date, all players from all teams wear Robinson's famous No. 42 on the back of their jerseys.

But have you ever wondered why every player on every team, plus coaches and umpires have No. 42 on their uniforms?

In this piece, we will explain the history of Jackie Robinson Day and why all players throughout the league are asked to wear No. 42 on this historic day.

Jackie Robinson Day History: Why do players wear No. 42?

April 15 is significant because this was the day that Robinson made his MLB debut all those years ago.

Back in 1947, he became the very first African American to play in Major League Baseball, breaking the league's color barrier and helping to correct one of the game's major mistakes.

In the film "42: The Jackie Robinson Story," starring the late Chadwick Boseman, Pee Wee Reese spoke to Robinson on the field while he was being heckled with racist taunts. He told Robinson that the following day, everybody on the team would wear No. 42 so that nobody would be able to tell them apart.

While this may not be a historically accurate depiction of the moment the Dodgers decided to do this, they ultimately picked a day for everybody to wear No. 42. According to Vin Scully, a teammate of Robinson's had the idea after Robinson received a death threat in a letter.

Jackie Robinson Day was first celebrated in 2004. A few years later, MLB requested that all players and coaches from every team wear No. 42 to honor Robinson.

Thanks to Robinson paving the way for other African American athletes, No. 42 is retired by all teams in Major League Baseball in his honor, though some teams had players wear the number after Robinson's retirement.

And so, Robinson's legacy lives on in baseball history. But that is the history behind MLB's choice to have players wear No. 42 on this special day.