I can sum up American history, at least the version I was taught, in four words: slavery, socialism, segregation, and assasination.
Slavery: You are black and you were a slave. The white man beat, raped, and tore apart the very fabric of black families. You were considered 3/5ths of a man.
Socialism: Woodrow Wilson was good. FDR was a savior. The white man hates you but you can make them suffer by giving government more power to redistribute wealth.
Segregation: The white man still hated you. He didn't want you to use the same toliet, water fountain, or swimming pool. The white man didn't want his kids to attend the same school as your kids. Only Big Government can create equality.
Assasination: And if you stand out, chose to be extraordinary, or speak with your own voice, you will be assasinated like Martin Luther King Jr., Malcolm X, and Medgar Evers.
They never mention free blacks and their impact on the American Revolution or prior to the Civil War. They never mention Reconstruction and the failures of Big Government for blacks in the South. They never mention the Booker T. Washington Era of prosperity and education or the Civil Rights Acts passed before the 1960's.
We were taught every reason America has to hate blacks. Why would we want to learn that history?