The copperhead Democrats in the North, and the Democratic Party of the South redeemed the slave states to slavery after the Civil War. They used the Black Codes to keep the Southern Black people in virtual, but not legal, slavery until John F. Kennedy sent the Fed. Marshals into the solid south (solidly Democratic Party) in 1963.
Southern Democrats immediately rejoined the Democrats of the North after the Civil War. Not one of the seceded Democrats was refuse readmission to the Democratic Party because they had declared war on our Republic. The Southern States are presently bastions of republicanism.
Is the post Civil War element of the Democratic Party still alive and well in the Northern States.?