Sumpter led to the disaster that was the war. All Appomattox was the last gasp of one side going down in total defeat.
South Carolina left the union.
They told DC to get off their land.
You say “all”?
Appomattox did not tidy things up. It stood the U.S. Constitution on its head.
Read the million page Federal Register - or is it two million pages now? - and then come back on this board and tell us the 9th and 10th amendments are intact, and there is no federal overreach.
The nation was much better off with those 750,000 people being killed and Washington DC becoming the dictator of everyone else's lives.