Or maybe America is actually far less racist than it was during the Civil War and opponents are magnifying what remains to try to make unjustifiable claims.
Can you cite any evidence or well-reasoned analysis to support this conjecture? The piece linked in the comment you replied to lays out a pretty rigorous case to the contrary.
So you want an entire rundown US history post-1865? If you want a social critique of the modern liberal "Euro-Critical" conception of racism and slavery, I'll refer you to Thomas Sowell's excellent collection of essays in "Black Rednecks and White Liberals"