Jackie Roosevelt Robinson was the youngest of five children born into a family of sharecroppers in Cairo, Georgia.

His middle name was a nod to the American President, Theodore Roosevelt, who had died 25 days before the arrival into this world of a man whose talent, and character, enabled a hugely significant social step to be taken in the history of his nation.

Robinson will always be known as the first African American to play Major League Baseball (MLB), something he achieved when he turned out for the Brooklyn Dodgers on April 15, 1947.

It was a hugely significant sporting landmark, ending more than 60 years of racial segregation within professional baseball. 

But it was hugely more significant than a sporting landmark, for it formed an influential part of a wider social movement within the United States towards racial integration.

Robinson faced a legion of racist comments and actions as he made his ground-breaking progress in his chosen sport. 

But very swiftly he became a potent emblem of hope and aspiration for his nation. Indeed, according to a poll conducted in 1947, the Dodgers' most audacious signing was the second most popular man in the US behind Bing Crosby.

The Reverend Martin Luther King Jr, one of the leaders of the movement for black civil rights in the US during the 1950s and 1960s, described Robinson as "a legend and a symbol in his own time", adding that he "challenged the dark skies of intolerance and frustration".

According to historian Doris Kearns Goodwin, Robinson's efforts "were a monumental step in the civil-rights revolution in America...[his] accomplishments allowed black and white Americans to be more respectful and open to one another and more appreciative of everyone's abilities".

Switching back to the domain of sport, the impact of Robinson's arrival in the top flight continues to be felt almost 50 years after he died of a heart-attack at his home in Connecticut, aged 53.

In 1997, MLB "retired" his uniform number of 42 across all major league teams - the first pro athlete in any sport to be so honoured. And on April 15, 2004, MLB also adopted the new annual tradition of "Jackie Robinson Day", on which every player on every team wears number 42.

Immediately after the Second World War, in which so many white and black recruits in the US Forces had fought and died alongside one another, there was a growing, if far from universal, inclination to reduce institutionalised segregation between white and black citizens. 

In 1948, President Harry S. Truman would officially end segregation within the US military, signing an Executive Order mandating equality of treatment and opportunity, and also making it illegal in military law to make a racist remark.

However, it was not until six years later that the last all-black unit within the US military was disbanded.

When baseball and other sports resumed after the war, the position was similarly one of segregation.

The Color Line, also known as the Color Barrier, was an understanding - rather than an explicit policy - arrived at in the 19th century within MLB and its associated Minor Leagues. Quite simply and arbitrarily, players of black African descent were banned from playing. 

While some light-skinned Hispanic players, along with Native Americans and Hawaiians, made their way into MLB, black players were obliged to compete in Negro Leagues that were set up in the early 20th century.

Before becoming the man to metaphorically burst through the Color Line, Robinson followed the only path then open to talented black baseball players. After being discharged from the US Army, in which he had been commissioned as an officer, he signed-up for the Kansas City Monarchs.

Fate was shifting him towards the critical moment of his sporting life - although it had already played a part in directing him towards baseball itself after he had excelled in four sports at Pasadena Junior College and subsequently at the University of California, Los Angeles (UCLA).

Robinson was a highly effective operator in basketball, American football, athletics and baseball.

In 1940 he won the National Collegiate Athletic Association long jump title with an effort of 7.58 metres, which would have earned him a silver medal at the London Olympics eight years later.

At a time when few black students played mainstream college football, Robinson was one of four black players in the unbeaten 1939 UCLA team.

In 1941 he signed up to play American football for the semi-professional, racially integrated Honolulu Bears before returning to California to take up a career as a running back for the Los Angeles Bulldogs in the Pacific Coast League. His football career came to an abrupt halt, however, when the Japanese attack on Pearl Harbor drew the US into the Second World War.

After a vexed Army career in which a legal case prevented him from seeing active service, Robinson worked briefly as a college basketball coach before gravitating to the game that would earn him fame.

While the Monarchs paid well, playing for them meant Robinson was, unhappily, locked into a hectic, packed and disorganised schedule.

At this time it was clear that the idea of black players taking part in MLB was at least a possibility - not least because of the obvious advantage of utilising their talents. 

In April 1945 Robinson and other black players took part in a trial match organised by the Boston Red Sox at Fenway Park. Extraordinarily, the management watching from the stands reportedly offered a range of racial abuse and it transpired the exercise had been designed to satisfy a liberal-minded and powerful Boston City councillor of the time.

However, other MLB teams were more serious about signing a black player - as became apparent on August 28, 1945 when one black man and one white man - Robinson, and Brooklyn Dodgers club President and general manager Branch Rickey - came to a professional and personal understanding of historic import.

In 2008, Rickey's grandson - Branch Rickey III - produced a book co-written with Lee Lowenfisch entitled Branch Rickey: Baseball's Ferocious Gentleman. It highlighted the resounding significance of this three-hour meeting of minds.

"I think it has been cheated out of all its deserved standing," Rickey III told Justice Hill, writing for MLB.com. "It's that meeting that everything good that happens in the aftermath springs out of."

Lowenfish told Hill that Martin Luther King gave Rickey a book containing the following inscription: "To Branch, who made my work that much easier."

According to Bob Kendrick, executive director of the Negro Leagues Baseball Museum, Rickey and Robinson met for the first time along with Clyde Sukeforth, who Rickey had assigned to scout for talent in the Negro Leagues.

"During that span of three hours, this decision was made and agreed upon," Kendrick told Hill. "You almost can't help but believe that this thing was meant to happen. These were the two people made to carry it out, and there were no forces that were gonna stop it."

Hill wrote: "In meeting, Rickey and Robinson helped America find an answer to the question of whether blacks and whites could exist in the same workplace."

Rickey III added: "Through courageous non-violence, they were going to take a stand on what was right. It wasn't an act."

He told Hill that his grandfather had been plotting since 1943 to bring a black ballplayer to the Major Leagues, but that he knew the person chosen needed to have a strong enough personality to survive the prevalent racial prejudice and make the vital experiment an obvious success.

Rickey III added that his grandfather's greatest talent was judging people, and that in his meeting with Robinson he recognised someone with the spirit to be a trailblazer.

After consulting his scouting reports, Rickey selected Robinson from a list of promising black players - including one, Josh Gibson, who was considered even more talented than the prime candidate. It was with a view to establishing him, initially, as a player with Brooklyn's feeder club the Montreal Royals.

Rickey asked Robinson if he could face the racial insults he would encounter without reacting angrily.

It was a huge question to be asked of a man who, up to that point, had established a reputation as someone who would boldly challenge any instances of racial prejudice.

While at Pasadena Junior College he had several run-ins with police and on January 25, 1938 he was arrested after vocally disputing the detention of a black friend, eventually receiving a two-year suspended sentence.

After receiving his commission in the Army, his career was put on hold when he boarded a bus with a fellow officer's wife and was ordered by the driver to move to the back - even though the Army had commissioned its own unsegregated bus line.

He refused, and although the driver backed down he summoned military police to arrest Robinson when the bus reached the end of the line. 

Robinson complained about racist questioning by the officer in charge, and it was recommended that he face a court martial. His commander refused to authorise this but Robinson was switched to another battalion and charged with multiple offences including public drunkenness - even though he didn't drink.

Robinson was acquitted by an all-white panel of nine officers at his court martial in 1944 - which had prevented him joining his original tank unit in action. Instead he served for a while as an army athletics coach before earning an honourable discharge in November 1944.

Robinson was aghast at Rickey's line of argument, reportedly asking him: "Are you looking for a negro who is afraid to fight back? To which Rickey reportedly replied that he needed a negro player "with guts enough not to fight back".

After obtaining a commitment from Robinson to "turn the other cheek" to racial antagonism, Rickey signed him on a contract worth $600 a month, equal to around $8,350 (£6,300/€7,300) nowadays.

"August 28, 1945, was a remarkable day," said Lowenfish.

Kendrick added: "In 180 minutes, one of the most monumental events in [history] happened with a handshake and a trust factor between a white man and a black man.

"To me, that's just amazing."

After this historic moment - the rest was history.

Having started at the relatively late age of 28, Robinson had an exceptional 10-year MLB career. He was the recipient of the inaugural MLB Rookie of the Year Award in 1947 and was an All-Star - a member of a combined team of American and National League players - for six consecutive seasons from 1949 through to 1954.

He also won the National League's Most Valuable Player Award in 1949 - becoming the first black player to receive this honour. Robinson played in six World Series and contributed to the Dodgers' win in 1955. He was inducted into the Baseball Hall of Fame in 1962.

After retirement he worked as the first black television analyst in MLB, and became the first black vice president of a major American corporation, Chock full o'Nuts. In the 1960s he helped establish the Freedom National Bank, an African-American owned institution in Harlem, New York.

After his death in 1972 his achievements on and off the field were recognised by posthumous awards of the Congressional Gold Medal - the highest award Congress can bestow - and the Presidential Medal of Freedom.

When Robinson had first featured in the Dodgers team, some of his team-mates had resisted his arrival. Their rumbling discontent was ended by the intervention of manager Leo Durocher, who reportedly told the players: "I do not care if the guy is yellow or black, or if he has stripes like a f***** zebra. I'm the manager of this team, and I say he plays. What's more, I say he can make us all rich. And if any of you cannot use the money, I will see that you are all traded."

Some opponents tried to rough Robinson up, and on one occasion he received a seven-inch gash in his leg. 

Soon after he began his Dodgers career, during a game against the Philadelphia Phillies on April 22, 1947, he was racially abused by some of the opposing players. Their manager, Ben Chapman, yelled from the dug-out that he should "go back to the cotton fields".

Rickey later recalled 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".

Robinson did, however, receive significant encouragement from several MLB players, including the Phillies' Lee "Jeep" Handley. Dodgers team-mate Pee Wee Reese once came to Robinson's defence with an often-quoted line: "You can hate a man for many reasons. Colour is not one of them."

In 1948, Reese put his arm around Robinson in response to fans who shouted racial slurs at him before a game in Cincinnati. A statue by sculptor William Behrends unveiled at KeySpan Park on November 1, 2005 commemorates this event by representing Reese with his arm around Robinson.

The UCLA Bruins baseball team plays in Jackie Robinson Stadium which features a memorial statue of the sporting pioneer.

However, these are far from being the only monuments to Robinson, who was celebrated in a 1949 song made famous by Count Basie entitled Did You See Jackie Robinson Hit That Ball?

A year later Robinson played himself in a film of his life - The Jackie Robinson Story.

Since then there have been a succession of TV features, films and documentaries celebrating Robinson's life and times.

His enduring monument, however, is the number of black players who followed him into MLB.

By the end of 1947, four others had made their debuts in MLB - Larry Doby, Hank Thompson, Willard Brown and Dan Bankhead. By the end of 1951 there were another 13 black MLB players. The tide was turning…

In 1950, after Rickey had left the Brooklyn Dodgers to become general manager of the Pittsburgh Pirates, Robinson wrote to him, saying: "Regardless of what happens to me in the future, it all can be placed on what you have done and, believe me, I appreciate it."