Interesting question, though for starters, it does seem plausible that the post-Civil War Reconstruction period might not have been as thorough as it was IOTL.....as I recall, as much as Lincoln genuinely loathed slavery, his primary objective was to reunite the Union, ideally as quickly as possible. But after his assassination, of course, that went pretty much out the window, and President Hamlin took a rather stronger route after the whole thing ended.
So with Lincoln surviving, we might not have had the state of West Florida created, and the Civil Rights Act of 1875 might not have been permanently enforceable(and no 1875 CRA may itself well butterfly the lesser known, but still important, Civil Rights Act of 1908 which forbade states to do certain things such as entirely outlaw interracial marriage or to mandate segregation, etc.).