How about an alternate history where the Negroes won the War of Independence?
I know that they were not oficially involved but that's why the Borg went back in time and struck Earth straight after World War III when they were too bloodied up already for a new fight.
A. The slaves sold out to the British Thrown in return for homerule of America.
B. 10 seconds after the British lose, Washington gets a hatchet to the back of his head because the colonies are in no shape to stand up to popular uprising at that exact point.
C. A coalition of African nations invades America to get all their kidnapped cousins back, rape and pillage everything and then plant their flag. Just imagine all these white people in pantaloons being thrown onto huge bonfires of crispy screaming white people.