Jack Roosevelt Robinson (January 31, 1919 - October 24, 1972) became the first African American Major League Baseball player of the modern era in 1947. The significance of this event in U.S. history is observed by the retirement by each Major League team of his uniform number, 42.

Born in Cairo, Georgia, Robinson was a football and baseball star at the University of California, Los Angeles, where he played with Kenny Washington - who would become one of the first black players in the National Football League since the early 1930s. His brother Mack competed in the 1936 Summer Olympics, finishing second in the 100m sprint behind Jesse Owens. After a spell at UCLA, during which time he met his future wife, Rachel Isum, Robinson served in the military during World War II, receiving an honorable discharge, after being exonerated at a court-martial for insubordination. Jackie played baseball for a while for the Kansas City Monarchs in the Negro American League where he caught the eye of a scout working for Branch Rickey.

Rickey was the club president and general manager of the Brooklyn Dodgers, and had the secret goal of signing the Negro Leagues' top players to the team. Although there was no official ban on blacks in organized baseball, previous attempts at signing black ballplayers had been thwarted by league officials and rival clubs in the past, and so Rickey operated undercover. His scouts were told that they were seeking players for a new all-black league Rickey was forming; not even the scouts knew his true objective.

Robinson drew national attention when Rickey selected him from a list of promising candidates and signed him. In 1946, Robinson was assigned to play for the Dodgers' minor league affiliate in Montreal, the Montreal Royals. Although that season was very trying emotionally for Robinson, it was also a spectacular success in a city that treated him with all the wild fan support that made the Canadian city a welcome refuge from the hateful harassment he experienced elsewhere.

Robinson was a slightly curious candidate to be the first black Major Leaguer in sixty years. Not only was he 27 (relatively old for a prospect), he also had a fiery temperament. While some felt his future Dodger teammate Roy Campanella might have been a better candidate to face the expected abuse, Rickey chose Robinson knowing that Jackie's outspoken nature would, in the long run, be more beneficial for their cause than Campanella's relative docility.

Robinson's debut at first base with the Brooklyn Dodgers on April 15, 1947 (he batted 0 for 3) was one of the most eagerly-awaited events in baseball history, and one of the most profound in the history of the U.S. civil rights movement. Although he played his entire rookie year at first base, Robinson spent most of his career as a second baseman. He also played many games at third base and in the outfield.

During that first season, the abuse to which Robinson was subjected made him come close to losing his patience more than once. Many Dodgers were initially resistant to his presence. A group of Dodger players, led by Dixie Walker , suggested they would strike rather than play alongside Robinson, but the mutiny was crushed when Dodger management informed the players they were welcome to find employment elsewhere. He did have the support of shortstop Pee Wee Reese, who proved to be his closest comrade on the team. The pair became a very effective defensive combination as a result. Pittsburgh Pirate Hank Greenberg, the first major Jewish baseball star who experienced anti-semitic abuse, also gave Robinson encouragement.

During the season, Robinson experienced considerable harassment both from both players and fans. The Philadelphia Phillies - encouraged by manager Ben Chapman - were particularly abusive. In their April 22 game against the Dodgers, they barracked him continually, calling him a "nigger" from the bench, telling him to "go back to the jungle". Rickey would later recall that "Chapman did more than anybody to unite the Dodgers. When he poured out that string of unconscionable abuse, he solidified and united 30 men." Baseball Commissioner Albert "Happy" Chandler admonished the Phillies, but asked Robinson to pose for photographs with Chapman as a conciliatory gesture; Robinson refused.

During Robinson's rookie season, he earned the major-league minimum salary of $5000. He played in 151 games, hit .297, and was the league leader in stolen bases with 29.

Robinson was awarded the Rookie of the Year award in 1947, and the Most Valuable Player award for the National League in 1949. He not only contributed to Brooklyn pennants in both years, but his determination and hustle kept the Dodgers in pennant races in 1950 and 1951 when they might otherwise have been eliminated much sooner.

Robinson's Major League career was fairly short. He did not enter the majors until he was 28, and he retired at age 37. But in his prime, he was respected and feared by every opposing team in the league. By the time of his retirement, he was disillusioned with the Dodgers, and in particular Walter O'Malley (who had forced Rickey out as General Manager) and manager Walter Alston.

Robinson was an exceptionally talented and disciplined hitter, with a career average of .317 and substantially more walks than strikeouts. He played several defensive positions extremely well and was the most aggressive and successful baserunner of his era; he was the first player to "steal home". By his talent and physical presence, he disrupted the concentration of pitchers, catchers and middle infielders. Robinson's overall talent was such that he is often cited as the best player of his era. It is also frequently claimed that Robinson was one of the most intelligent baseball players ever, a claim that is well supported by his home plate discipline and defensive prowess. Robinson was regarded as a fierce competitor in the truest sense; he never gave up on a game if his team was losing, to the point that he would try everything to avoid being the last man out for his side.

Robinson retired from the game on January 5, 1957. He had wanted to manage or coach in the major leagues, but received no offers. He became a vice-president for the Chock Full O' Nuts corporation instead, and served on the board of the NAACP till 1967 (at which time he resigned, protesting the lack of younger voices in the movement). In 1960, he involved himself in the presidential election, campaigning first for Hubert Humphrey, and then meeting both Richard Nixon and John F. Kennedy; citing his record on Civil Rights, Robinson supported Nixon. After Nixon was elected in 1968, Robinson wrote that he regretted the endorsement. He campaigned diligently for Humphrey in 1968.

He was inducted into the Baseball Hall of Fame in 1962, his first year of eligibility. On June 4, 1972 the Dodgers retired his uniform number 42 alongside Roy Campanella (39) and Sandy Koufax (32). Robinson made his final public appearance on October 14, 1972 before Game 2 of the World Series in Cincinnati.

Crippled by the effects of diabetes later in his life, and distraught by the death at age 24 of his eldest son, Jackie Jr, Jackie Robinson died in Stamford, Connecticut on October 24, 1972 and was interred in the Cypress Hills Cemetery in Brooklyn, New York. For details, see Jules Tygiel's book, Baseball's Great Experiment.

In 1997 (the 50th anniversary of his major league debut), his number (42) was retired from all MLB teams. In 2004, Major League Baseball designated that April 15 each year would be marked as "Jackie Robinson Day" in all their ballparks.