In the Battles of 1864, the two main ones were the Battle of Cold Harbour, and the Battle of Atlanta. At the beginning of 1864, Abraham Lincoln put General Grant over all the armies and put General William Sherman in charge of the army that Grant used to have. This change finally brought a face-off between General Grant and General Lee who had been the most successful generals thus far.
They fought from May the 31st to June the 12th 1865, but the hardest day of battle was on June the 3rd. The Confederates put up a fort, and when the Union army rushed to attack them, the Confederates would beat them back easily. At the end, the result was like the battle of Antietam, it produced significant Union casualties without any progress being made. General Grant forever regretted this battle, and the confederates won considerably. This battle happened to be General Lee’s last victory, for from then on he was just running and retreating.
The Battle of Atlanta was a campaign that was revolutionary in the history of war, for General William Sherman decided to operate deep in enemy territory without the benefit of supply lines. This would have never worked on paper, but it was incredibly efficient and productive, even though it was considered unprofessional. What Sherman did was that he targeted industry, infrastructure, and civilian property. When he and his team found railroad tracks, they just took them off, bent them, and put them around trees. When he reached Atlanta, he carried out a siege, and then after capturing it burned the whole city to the ground. He then captured the southern state capital of Milledgeville and then humiliated Georgia and the Confederacy. The Battle of Atlanta was a short series of struggles that ended with a Union victory.
These were the main battles of 1864, and later on, in 1865, the Union forces managed to win the war and beat the confederates.