What were the Ebb and flow of civil war?

Answer 1

As Sherman had warned Southern friends, they would enjoy successes in the first half, but come to grief in the second half.

It was Robert E.Lee who took the Confederates close to a winning position by invading the North in the summer of 1862, but he lost the Battle of Antietam, and then Lincoln was able to play his political stroke of turning it into a war on slavery, to keep the British from intervening on the other side.

The following summer, Lee tried again to invade the North, but was defeated at Gettysburg, the same day that Grant liberated the Mississippi.

Ater that, it was generally downhill all the way for the Confederates, although Lincoln could still have lost the General Election of 1864, which would have been very serious indeed for the Union.