The Emanicipation and re3construction period was a success actually those periods and the Civil War created the 2nd American Republic. It is clear that the original Republic after the Revolutionary War was for a limited group "white men ",who owned property.The Civil War, Emancipation the 13th ,14th and 15th Amendment's along with the Reconstruction opened a 2nd Republic for all men and later for women also.
Keep in mind that the Slaves freed themselves.Large numbers left their "holders" control to meet with the "Union " Forces even when "Lincoln's" position was not in favor of emancipation.
Finally 200,000 African and African Americans finally were permitted by Lincoln to fight in the Civil War and 37,000 paid the extreme sacrifice.