What led to resentment and violence amping many white southerners after the civil war

The resentment began with the placement of "reconstruction" from the Northern government, Abraham Lincoln originally put this in place to help the south, but after his death, it was corrupted by other government officials. The south felt as if they had no decision in what happened on their land, since it was mostly over run with Northern soldiers. Also, they were basically forced to intermingle their lives with other races, which they never had to do before; this caused a great push from the south and ultimately ended with the KKK being initiated.