(Before I start - be sure to check out Robert Bateman's writing on Chickamauga at Charles Pierce's blog. An actual professional soldier and historian, who's always enlightening...)
So - today is the second day of the battle of Chickamauga. The first day had brought attacks all along the lines, most of them going in on their own, really, without much coordination. Nothing had been decided - the battle would be resumed in the morning.
But first, Bragg decided to reorganize his army overnight. He appointed Leonidas Polk commander of his right wing. He appointed James Longstreet commander of the left wing. Longstreet himself arrived on the battlefield sometime after dark on the 19th - got off a train, rode some distance to reach the battlefield, and was put in command of half the army. Bragg also had the idea that they should all attack at dawn on the 20th - whether this idea made it out of his head or not is an open question. In any case, none of his generals seemed to have any idea they were attacking at dawn, though it is hard to tell if that is because Bragg never told them to or because none of them much cared what Bragg wanted. None of them, not Bragg or anyone else, seemed to have put much effort into making sure they knew what they were supposed to do.
So the fighting started back up on the 20th, at about 9:30 or so, quite a bit after dawn. It started, again, on the Confederate right/Union left. The Yankees had used the night and morning to put up fortifications along this part of the line, with predictable results. This time, some of the Rebels did get on their flank, but only a few - most of them ran into the main lines, now behind cover, and were shot to hell. That kept up most of the morning; Longstreet, on the rebel left, was in no hurry to get going, so most of the action stayed where it started. This meant a couple things - one was that the Union was able to shore up its lines on the left and deal with the rebels who did manage to get around the flank. But another was that as Rosecrans kept moving men to their left, he started to lose track of where people were. And that had consequences.
Basically, two things happened, more or less at the same time, that brought on disaster for the Union. Both, I would have to say, had been coming.... One is - Rosecrans gave a bad order. He had a reputation for losing composure in battle, and he did it here - he had been shuffling troops around the battlefield, reacting to every threat, sometimes without quite thinking about what else was happening - and he lost track of where people were. He was also dispatching orders very quickly - he wrote some, his chief of staff, James Garfield, wrote some, and other staff officers wrote others - the orders were not always clear, and the group of them were not always checking against one another to make sure everything was accurate. The specific incident went roughly like this: there were three divisions in a row, left to right, near the center of the union line - Reynolds, Brennan and Wood. Most of the fighting was taking place on the left, and troops were being moved from the right and center to reinforce the left. In the middle of this, Brennan was ordered to move to the far left to meet the threat. Someone pointed out that if Brennan moved, it would leave a hole in the line - so Rosecrans ordered Wood to move into the space Brennan vacated, to support Reynolds. The problem was - all these orders got gummed up. Brennan didn't go anywhere until his replacements arrived; his division hadn't moved when Wood received his orders to move next to Reynolds. Now - maybe another general, another day, would have decided if the order’s conditions weren’t met, he shouldn’t follow them - or would have sent someone back to HQ to say that the division he was supposed to replace was still there. But Wood and Rosecrans had been feuding, over the giving and following of orders - Rosecrans had made a point, during these disputes, that an order was an order and Wood had better follow it - so Wood was not going to take the heat here. He had an order, in writing - he would follow it to the letter come hell or high water...
...Or Longstreet’s corps. Because that was the other thing happening - James Longstreet was preparing an attack on the center of the Union line even as Wood pulled out of the line. And when James Longstreet attacked, he attacked. He had a reputation for moving slow - for having his own ideas about battles and being stubborn about them - but when he moved, he moved hard. (He was a lot like George Thomas in that.) And here - unlike everyone else in this battle, he prepared this attack: he stacked his men 5 lines deep, planning to drive through any opposition - sent them in - right where Wood used to be. That pretty much did it. They punched straight through the middle of the union line, and proceeded to rout everyone to their south. It wasn't immediate - south of the break, the Yankees put up a fight for a while - but Longstreet's men could get around behind them, and every line broke. Before long, the right side of the Union army was all gone, heading west as fast as they could go - taking with them a fair part of the army's high command. Rosecrans, McCook and Crittenden, their much more talented division commanders like Phil Sheridan and Jeff Davis (the Indiana Jeff Davis, who had only two things in common with the Mississippi Jeff Davis - his name and the fact that he commited a hanging offense during the war but didn't hang. The Indiana Davis shot a superior officer dead in cold blood in a hotel lobby, but ended up commanding a corps. It helped to be friends with governors back then.) And, we can't forget, Charles Dana, assistant secretary of war, attached to the army to spy on Rosecrans and keep him moving.... Dana ran with the rest of them, but did more harm than most, interfering with a counterattack that might have stabilized the situation. John Wilder's infantry brigade had been equipped with Spencer repeaters - they came up in the middle of this fight, and determined to counterattack. They were a brigade strong, but they could get off seven shots at a time, which gave them the firepower of a couple divisions - they were an elite unit, and might well have tipped things. But Dana thought the day was lost and demanded an escort off the battlefield - by the time Wilder had sent him along, the chance was lost.
Things were almost as bad on the union left - Longstreet's attack cut the army in half, and his men were trying to roll up to the Union left like they did the Union right - but that didn't quite work. Thomas' men hadn't moved all day - their lines were still as solid as ever. All those reinforcements, people like Wood's men, were already on this side of the battle - quite a few of them got into line along a series of hills called Horseshoe Ridge. And - as things started to fall apart, the last of Rosecrans corps commanders, George Granger, appeared with most of his men - they came in just in time to hold Horseshoe Ridge. And then?
Over and over during the war, armies who looked like they had swept the field clear, ran into a force that stood up to them and stopped them cold. It happened at Shiloh, in the Hornet's Nest. It happened at Chancellorsville, where on May 2, Jackson caved in the union right, but on May 3, both sides faced off in a day long toe to toe slog. It happened at Stone's River, first when Sheridan's division held, later in the Round Forest. And it happened at Chickamauga, on Horseshoe Ridge. The Confederates had driven off half or more of the army - had gotten behind the half that stayed - but the Union threw up a defensive line, and the Rebels proceeded to simply throw themselves at it, over and over, without any further coordination, no more attempts to get around the Yankees, nothing. There were probably better reasons for it than for most of the troubles the Confederates had - John Hood had been in direct command of the attack, and he'd been shot down, leaving no one quite in charge. Longstreet exercised very little control over this part of the battle. Bragg, obviously, played no role. It was left to the brigade and division commanders to keep attacking, and they did, but with no plan beyond attacking what was in front of them.
It was still a close thing. The rebels kept coming. There were astonishing stands made - by the 21st Ohio, say, a regiment armed with Colt repeating rifles, who held off attack after attack, all day, before being left behind, without any ammunition. Desperate charges and counter charges, dirty tricks (at one point, a Confederate unit appeared, and were challenged by the Yankees - who are you? asked the Northerners; Jeff Davis' men, came the reply - honest, I suppose, but you do recall that [Indiana] Jeff Davis commanded a division in the Army of the Cumberland?) It all ended after dark, with more confused fighting and people being captured without knowing who got them... but the Union army got away, and hoofed back to Chattanooga, where they were quickly bottled up... but that's another battle.
So there it was. 34 or 35,000 casualties total, the second highest of the war. The Confederates lost more men shot, having spent two days attacking, and the end of it, relentless attacking, often against men dug in. The Union almost evened the numbers because of their prisoners. It was a very significant Confederate victory - they broke Rosecrans' army, chased half of it away, shot up all of it - they restored a lot of their fortunes in this battle. Though - well, we can discuss what happened next when we get to Chattanooga. The battle ruined men - Rosecrans was doomed, and was relieved once Ohio held their elections in a month or so, replaced by Thomas. McCook and Crittenden were soon gone. Others - Thomas particularly - were made by the battle. Some, like James Garfield, Rosecrans' chief of staff, saved their reputations by going back to he battle - Sheridan and Davis left, but did enough to try to get back to be spared the fate of McCook and Crittenden. On the Confederate side - well - that has to be another post. Bragg here won his biggest victory - but the army hadn't gotten to Chattanooga to besiege Rosecrans' wrecked army before the rest of the rebel generals were howling for his head. In that army, fighting the Union was a distraction from fighting with one another...