You would not believe this one I found online.
A Guyanese was the first black footballer to ever play for Britain, he was one of the best and "sired a familly" there too. 
http://www.black-history-month.co.uk/articles/andrew_watson.html
First Black footballer, Andrew Watson, inspired British soccer in 1870s
A worn photograph, some yellowing newspaper files, a cryptic comment and a brief mention in a dusty census tome have been unearthed in Scotland in what has been described as the most important discovery in the history of Black footballers in Britain, the Chronicle has learned.
Andrew Watson of Queens ParkFC, Glasgow, circa 1879, courtesy of the Scottish Museum
"We believe the findings, dated between the 1870s and 1880s, could prove that the first black British footballer was Andrew Watson who played for Queens Park (Glasgow) and Scotland, said Ged O'Brien, director of the Scottish Football Museum and leading member of the Association of Sports Historians.
Born May 1857 in British Guiana [now Guyana], Andrew Watson lived and sired a family in Scotland and came to be known as one of the best players in the whole of Britain.
Andrew Watson was first known to be pioneer of black football in britain but he wasnt if that site means fully black well quess he is.
Most people know that Arthur Wharton was the first black footballer in Britain the dating of Andrew watson is wrong, which was found out by Phil Vasili a Historian on black footballers in england
Anyways heres a little bit on Arthur Wharton
Arthur Wharton - The First Black Footballer
During the 1894-5 season Arthur, the fastest man in Britain between 1886-8, played three games for United's first team - in goal. It wasn't some quirk of Blades management to restrict one of the fastest men on Earth to a small area at one or the other end of the pitch. Arthur had played in goal for Darlington, Preston North End and Rotherham before being enticed to Sheffield by Tom Bott, a United director and unofficial team manager. Bott had been Arthur's manager during his professional running days. What may have made Arthur's mind up was the additional offer of taking over the Sportsman Cottage pub in Button Lane. He liked a drink.
Unfortunately for Arthur United had also signed a very promising 19 year old - and 13 stone but bulging fast goalkeeper, William "Fatty" Foulke. For the first time in his sporting life Arthur could not dislodge his competitor for the first team spot. He played only three games, against Leicester Fosse, Linfield of Belfast and Sunderland. In this last game at Roker Park, Arthur made his debut in the first division. The 'Cutlers' as the Blades were then known, lost 2-0. Arthur, the goalkeeper with the 'prodigious punch' was at fault for one. His prodigious punching letting him down when he went to fist the ball away and missed it completely.
During the 1890's to be a goalkeeper you had to be mad, bad or dangerous to know. Goalies could handle the ball anywhere in their half of the pitch and could be charged down with or without the ball. Trying to grab the ball in a crowded goal mouth, the goalie needed the protective and attacking skills of a Thai kick-boxer. Arthur didn't just fist the ball away with his 'prodigious punch', he had to get his retaliation in first.
There are few of Arthur's personal effects still around. His bible and a few photographs with his writing on are what's left. I'd love to have known if 'Fatty' ever went to the Sportman's Cottage for a few scoops after - maybe even before - a game. Both were larger than life characters, similar men in many ways. Both were outsiders; Arthur because of the reaction to his colour; and 'Fatty' because he was, well, fat! Both played in a very violent position and seemed to enjoy- prosper - on the flow of adrenaline that surged after a punch-up with a few forwards in the goal mouth. Arthur was a womaniser. Did he and 'Fatty' ever go out on the 'pull'? We'll never know if they even spoke to each other, but the idea of the two being muckers throws up some great scenarios.
Arthur was past his best when he joined United. He'd had a great career in sport, but the high points were in the 1880's. He was AAA 100 yards champion in 1886, setting a world record of 10 seconds. He retained the title in 1887. He then turned professional and won the unofficial championship by winning the September Handicap at Queens Ground, Sheffield in 1888. Arthur's greatest football moment was playing in the semi-final of the FA Cup in 1887 for Preston NE, against West Bromich Albion. Although hotly tipped to win the FA Cup, Preston lost 3-1. Arthur also played professional cricket until at least his forties.
Arthur was 'lionised' in the communities in which he lived. He became a northern working-class hero, despite coming from a wealthy Ghanaian background. Like any other black person he suffered racism, but he was not a passive victim. He fought back - this is documented - an was a proud man without being arrogant.
For 67 years he lay burried in an unmarked grave in Edlington Cemetary. Football Unites - Racism Divides have raised the money to fund the writing of Wharton's biography. Enough money was raised to place a gravestone on Arthur's plot - he is now visible once more. A timeline of Arthur's life
Born
Year 1865
Born in Accra, Gold Coast (Ghana), West Africa. Father Methodist Minister and Missionary from Grenada (West Indies). Mother related to Fante Royal family (Gold Coast). Both parents have part Scottish ancestry. 