Today is the 150th anniversary of the fall of Atlanta, the event, more than any other single event, that marked the end of any chance the Confederacy had to win the Civil War. Militarily, the issue was probably not in doubt - but there was an election in 1864, and Abraham Lincoln stood a chance of losing, enough of a chance that he made serious plans about what to do in case he lost. His opponent was George McClellan, one time self-declared savior of the republic (though to be fair, he was not alone in thinking he was chosen to save the country) - McClellan proved a terrible battlefield general, with no stomach for the war - and politically very squeamish about pushing the war into political realms. But it was a political war, more and more, and the Democratic party, by 1864 was becoming very defeatist, not least because they had no desire to win a war that would free the slaves and make citizens of all black men. McClellan himself didn't go as far as the party did - he was not prepared to abandon the war or the south - but if he won, he would have been hard pressed to continue the war, and in any case, he was not a very forceful leader.
And the voting looked like a close thing, there for awhile. Grant's Virginia campaign was a bloodbath that ended in a siege of Petersburg. Sherman's George campaign brought less bloodshed (as both sides had more room to maneuver, and more inclination to do so), but appeared to be ending in just as much of a stalemate as the east. But the Confederate government saw things differently - they did not see the advantages of dragging out the campaign as far as it would go - they wanted to win a battle and drive the Yankees off... So back in July, they put John B. Hood in command of the Atlanta defenses, under the clear assumption that he would take the battle to the Federals - he did, fighting a series of bloody battles, that he lost, making the outcome inevitable. And on September 2, he set fire to the city and marched away, and Sherman had Atlanta, and fairly won.
There was a lot more killing to come. Hood headed off west and pestered the Union troops in Tennessee for some time - ending in more bloodbaths, at Franklin and Nashville. Lee held on in the east another 6 plus months, but his situation was desperate. Campaigns in the Shenandoah went for the Union. Sheridan in the east and Sherman in the west would eventually go on scorched earth campaigns to try to starve out the Confederate armies (And punish the Confederate civilians). And so on. But there was no changing the ending, really, after Atlanta fell, and Lincoln's reelection became assured. And so, today - it is worth remembering and celebrating.