One of the sources of many modern political woes in the United States is that Reconstruction after the U.S. Civil War ended before the South was reconstructed.
This could have, and probably should have, been handled differently. Some things that we should have done instead:
* Execute all of the Confederate regime's elected officials, senior political appointees ("officers" of the regime's government), judges, military officers and spies for treason.
* Execute all pro-slavery clergy.
* Permanently remove the right to vote of every Confederate government official, every every Confederate solider who was a volunteer, and everyone who had ever owned a slave as an adult. Make it a crime for any of these persons to bear arms.
* Seize all real property and all other significant property (including all firearms and military equipment) of the families of everyone executed due to these Reconstruction mandates, everyone whose right to vote was lost, everyone who served voluntarily in the Confederate military and died, and every slave owner. Use this seized property for reparations to the freed slaves and exiled Native American tribes. Reparations for former slaves would be in a concept something alone the lines of "40 acres and a mule" affording freed slaves the resources necessary to survive as subsistence freeholder farmers.
* Seize all property of pro-slavery churches and pro-slavery or pro-confederacy political or civic organization. Use this seized property as part of the funding for integrated, universal, free public educational institutions and libraries.
* Convert all states that seceded to unorganized federal territories eligible for readmission to the United States as states only when they we sufficiently reconstructed. These would be under military rule for a decade or two in any given place before territorial self-rule subject to Congressional direction and a federally appointed territorial governor would be permitted.
In this kind of scenario, the South might have actually reconstructed itself.