Lincoln was a politician of his time. At first he didn't believe that black people were the equal of white. The Missouri Compromise was about keeping the slave state if the state would be a member of the Union.

Lincoln probably changed quite a bit in office, maybe not honoring equality, but at least alleviating the suffering and the continuance of slavery.

However, the American Civil War was fought over the issue of slavery despite the "Confederate" deniers. State's rights had to do with slavery, primarily.