This is just disgusting. There is no way of telling the history of the United States without discussing the institutionalized oppression of Jim Crow, and the Civil War was unambiguously about slavery.
I mean, read The Declaration of Immediate Causes, South Carolina’s explanation for seceding, in which the state of South Carolina itself announces that it is leaving the Union due to “increasing hostility on the part of the non-slaveholding States to the Institution of Slavery.” It then encourages other slave-holding states to secede (which most did), so that they could create a nation, The Confederate States of America, in which there will be less hostility toward slavery.
Insofar as the Civil War was about states rights, it was about a state’s right to decide whether slavery should be legal. People knew that in 1860, and they should damn well know it now.