It was the end of a civil war in which four million slaves were freed, but which failed to bring true freedom to the people on whose behalf it had largely been fought. It was called the "Reconstruction Era" because its purpose was to rebuild (and heal) a war-torn nation, but which saw almost as much violence and destruction as actual reconstruction. And it brought the vote and other rights to the former slaves of the South for a time, only to see those rights taken away almost overnight when the Reconstruction Era ended in a corrupt political deal, giving the White South almost everything it wanted.
Confederate capitol of Richmond, 1865 (the end of the war)
Much has been written about the military conflict called the "Civil War" (fought between North and South), but not as much has been written about the postwar Reconstruction period, which is perhaps even more complex politically than the war itself. Indeed, some historians have even called it the "Second Civil War," because it was characterized by anarchy, chaos, and even (at times) armed conflict; between former Union soldiers occupying the South, and former Confederate soldiers joining the Ku Klux Klan and other terrorist organizations; who were trying to undo all that the North had fought and died for.