Why are MLB players wearing No. 42 jerseys today?

Now honoring No. 42: Jackie Robinson Day in majors - The San Diego Union-Tribune

The only day MLB players can wear No. 42? Jackie Robinson Day

Mariners at forefront of establishing Jackie Robinson Day

All players wearing 42 wrong way to honor Jackie

MLB celebrates timely Jackie Robinson Day

Yankees' Mariano Rivera Is the Last No. 42 - The New York Times

What Happens to All Those No. 42 Jerseys? - The New York Times

MLB allows more players to wear No. 21 to honor Roberto Clemente – NBC Sports Chicago

Why are Boston Red Sox players all wearing No. 42 jerseys? Jackie Robinson day across the MLB

Cincinnati Reds - Today in Reds history 2007: Reds right fielder Ken Griffey Jr. sought permission from then-Commissioner Bud Selig and Robinson's widow, Rachel, to wear No. 42 on April 15. From

Why is today Jackie Robinson Day? The reason MLB players wear 42 & more to know about baseball's annual April 15 tribute

A's, Astros walk off field in protest, game postponed

Philadelphia apologizes for 'tremendous racism' against Jackie Robinson - The Globe and Mail

Last player to wear No. 42 for each MLB team