The Historic Jamestowne site said that Pocahontas married Kocoum in 1610 ("Should I marry Kocoum?"), a year after Smith left Virginia. Kocoum was a real person who existed, but he wasn't killed by the bumbling British man-boy Thomas like the film shows. In the film, Chief Powhatan wants Pocahontas to marry the stoic Powhatan warrior Kocoum, even though Pocahontas is resistant. But according to the written history of her life on the website for Historic Jamestowne, which is part of Colonial National Historical Park, Disney definitely didn't stick to history's script. A lot is also not known about Pocahontas - she lived over 400 years ago - and there are many different accounts.
Of course, history buffs knew the story of Pocahontas long before Disney made a movie about it, but, once the animated movie hit screens, those same buffs were enraged that the film perpetuated historical inaccuracies and romanticized the legend (as in, it literally made the legend romantic). Pocahontas turns 20 years old in June, and the animated classic is a still a favorite of mine - hello nature-friendly songs like "Just Around the Riverbend" and "Colors of the Wind"! But even though I was a fan, I understood that Disney took some significant liberties with a real-life historical figure when it chose to Disney-fy Pocahontas. And though fans of Disney are used to going along with talking-animal sidekicks, it was a little harder to swallow Disney significantly changing the history of Pocahontas for its 1995 movie. To me, all movies require at least some suspension of disbelief to be enjoyed, and Disney animated films are the rule, not the exception.