Celebrated at MLB ballparks, on that one day, all players, coaches, and managers on both teams, and the umpires, wear Robinson's uniform number, 42.

Initiated for the first time on April 15, 2004, the festivity is a result of Robinson's memorable career, best known for becoming the first black major league baseball player of the modern era in 1947.

On April 15, 1947, Jackie Robinson made his major league debut for the Brooklyn Dodgers at Ebbets Field before a crowd of 26,623 spectators, more than 14,000 of whom were black.

[8] In 1997, MLB retired his uniform number, 42, across all major league teams; he was the first pro athlete in any sport to be so honored.

Fifty years after that historic event, in April 1997, I was proud to join Rachel Robinson and President Bill Clinton at Shea Stadium to honor Jackie by retiring his uniform number 42 in perpetuity.

"[10][11] It began that Thursday morning with Sharon Robinson, ringing the ceremonial Opening Bell at the New York Stock Exchange.

[15] April 15, 2007, was the 60th anniversary of Jackie Robinson's major league debut, with ceremonies held at Dodger Stadium in Los Angeles, California.

During the 2007 regular season, Ken Griffey Jr. called Bud Selig to ask for permission to wear number 42 on Jackie Robinson Day.

[19]) Selig embraced Griffey's gesture and encouraged other Major League Baseball clubs to have a player wear number 42 on Jackie Robinson Day as well.

[18] "This is supposed to be an honor", Minnesota Twins outfielder Torii Hunter told USA Today, "and just a handful of guys wearing the number.

"[18][20] Cleveland Indians pitcher CC Sabathia, who decried the lack of African-American players in the game in March 2007, told USA Today that "It kind of waters it down.

"[21] Randy Wolf, who was playing for the Dodgers at the time (currently a free agent) allowed six hits and three runs in six innings and struck out seven.

The only other pitcher in major league baseball history had gone as many as 25 straight road starts without losing — Allie Reynolds had a 25-game streak in 1948–1949.

"[21] "Oh Happy Day," a Robinson favorite, was sung by The Brookinaires Gospel Choir from The First African Methodist Episcopal Church.

[21] On April 15, 2008, the 61st anniversary of Jackie Robinson's major league debut,[3] over 330 team members wore number 42, which was up from about 240 the previous year.

[22] When the teams took the field, all players, managers and coaches were wearing number 42, and this was repeated at all other 14 ballparks that had scheduled games that day.

"[3] The celebration for the 2009 season, commemorating the 62nd anniversary of Robinson's debut, included the dedication for the Jackie Robinson Rotunda at Citi Field,[25] the New York Mets' new home in Flushing Meadows prior to the Mets playing the San Diego Padres in the second regular season game to be played there.

Owned by former Dodger owner Peter O'Malley, Historic Dodgertown hosted the 2014 celebration by putting on a minor league exhibition game.

The statue, located in the stadium's left-field plaza, depicts Robinson sliding into home plate as a rookie.

[33][34] In response to the police shooting of Jacob Blake in Kenosha, Wisconsin, professional athletes in the United States boycotted by refusing to play in their scheduled sporting events.

[36] The player boycotts extended to Jackie Robinson Day,[37] with the August 28 game between the Houston Astros and Oakland Athletics being postponed.