Within Our Gates is a 1920 silent film about race relations directed by Oscar Micheaux. Wikipedia claims "it is the oldest known surviving film made by an African-American director".
I find the exaltation of "the North, where the prejudices and hatreds of the South do not exist" a bit hard to buy. It seems to move a bit slowly, and it's hard for me to get involved. Too much romance for my taste, maybe.
It's listed in the book 1001 Movies You Must See Before You Die, which says the film "has immense historical value" and describes it as "powerful, controversial and still haunting in its depiction of the atrocities committed by white Americans against blacks during this era". A Film Canon calls it "a powerful, sophisticated inversion of Birth Of A Nation."