Soon after the Second Corps arrived at Falmouth, Burnside reviewed the troops. Instead of cheers he received catcalls. Burnside wrote to Lincoln blaming the operation's failure on the lateness of the pontoon bridges but taking full responsibility. He came up with a new plan, to outflank Lee and strike him while he sat in Fredericksburg. On December 26 he ordered supplies for 10 days and the men to have 3 days cooked rations. On December 30, in the rain, he moved the cavalry to cross the Rappahannock over the northern fords with the infantry to follow. A telegram arrived from Lincoln which caused Burnside to countermand the order and halt the army. Burnside made for Washington.
Two of Burnside's Brigadier Generals, John Cochrane and John Newton of Smith's corps under Franklin's Grand Division, were in Washington explaining to Lincoln how the army had lost confidence in Burnside. Spurred on by Franklin and Smith, the two junior generals claimed that Burnside's new plan was doomed to failure. Burnside suggested the officers -- he wasn't told who they were -- should be dismissed. He also suggested that others, including General-in-Chief Henry Halleck, be let go. He offered his resignation. Lincoln declined it and sent him back with orders to proceed with his plan, but to be cautious. Burnside could hardly have been happy with this order, but he went and continued with his operation.
By the time he got back and began to move his army it was January 20, 1863. The plan was sound, but Burnside was hit once more with foul luck. By that evening the wind whipped up and it started to rain. The next day, the rain fell in torrents. The road was churned into a terrible muck. For almost four days the rain fell, and the army tried to move in the mud. Morale fell with the rain. Horses and mules died of exhaustion or were sucked into the quagmire. Men floundered in the mud, while gun carriages sank up to the axles. The army advanced barely 1 1/2 miles. The plan was cancelled and the army went back to camp. The Mud March was over.
Burnside's officers condemned the Mud March and their commander, but Hooker went further than anyone. He told a newspaper reporter that Burnside was incompetent and the Administration in Washington should be replaced by a dictatorship (in the classical sense, of a military man in charge of the country until the crisis was over).
Burnside was livid. On January 23 he wrote General Order No. 8, which called for Hooker's removal from service. He also called for the removal of Franklin, Maj. Gen. William Smith, and various other officers including Newton and Cochrane, whom he had identified by this time. Burnside didn't have the authority to dismiss these officers, though, without a court martial. So, he gave the order to Lincoln with his resignation. Lincoln had to accept either the order or his resignation.
Lincoln accepted Burnside's resignation, but only from his command and not from the army. He removed Franklin from command, but he later gave Franklin a small command in Louisiana. Sumner was relieved of command by his own request, and given a post in Missouri. He went north to rest for a while, but took sick and died in Syracuse, New York.
Hooker was given command of the Army of the Potomac. This may seem strange, given his condemnation of the government and Burnside, but Hooker still had friends in Washington. He also had a reputation as a competent and aggressive general. Lincoln needed someone and Hooker seemed the best of the lot.
The mark of a great general is not his battle plans, but how well he adapts once the battle commences. Burnside's initial plan was sound, but it was doomed almost before it began due to the pontoon bridge delays. Even still, Burnside's stubborn streak forced him to keep to a plan that became impossible to implement. His command structure hurt him as his corps commanders were forced to go through another layer of command. Perhaps he felt that his grand division commanders would be an asset to him, but in practice his orders had to be interpreted through them. If Meade, for instance, could have skipped Franklin and gone straight to Burnside, it is possible that he would have received the reinforcements he needed. Once the battle began, Burnside was too slow and distant to react to the slaughter. His Mud March plan actually had merit, but the weather and his subordinates conspired against it. It's interesting to note that in the opening moves of the Chancellorsville campaign, Hooker successfully implemented the correct plan for attacking Lee at Fredericksburg with what was essentially a variation on Burnside's Mud March.
Fredericksburg was one of the worst tactical disasters to befall the Union armies. The slaughter was horrible for no gain. While other battles were bloodier, few were as one-sided. The Army of the Potomac was thoroughly demoralized. It wouldn't take part in any sizeable operations for several months. It wasn't a complete strategic disaster, though. The Federal artillery on Stafford Heights convinced Lee not to move over to the offensive. Fredericksburg became the Army of Northern Virginia's winter camp. The battle, a sore point in the Union, would be remembered throughout the next year. During the Chancellorsville campaign in May of 1863, Maj. Gen. Sedgwick's Sixth Corps would take Marye's Heights temporarily. At Gettysburg in July of that year, Confederates retreating after the slaughter of Pickett's Charge heard the Union defenders of Cemetery Ridge chanting "Fredericksburg! Fredericksburg!"
Ironically, the general in charge of the Army of the Potomac at Gettysburg would be Meade, the commander who made the most headway at Fredericksburg. Hooker would lead the Army of the Potomac into the debacle of the Battle of Chancellorsville, where Meade was a corps commander. Soon after, Meade took over from Hooker, leading the army until the end of the war (albeit under Ulysses S. Grant for most of that time).
Burnside never seemed to get over Fredericksburg. Lincoln was loathe to lose him and transferred him to the Department of the Ohio. During his assignment he marched on Knoxville, Tennessee and was beseiged there by Longstreet until relieved by one of Maj. Gen. William T. Sherman's columns. For capturing Knoxville he received the thanks of Congress. He was transferred back to the Eastern theatre.
He reported for a time to Grant directly, so he wouldn't have to report to Meade, his junior. He seemed reluctant to commit troops at Spotsylvania and The Wilderness, perhaps with Fredericksburg in mind. During the seige of Petersburg, an officer with mining experience suggested that the Union could dig a tunnel under the Confederate earthworks and detonate explosives beneath it. Burnside championed the project, but was also partly responsible for its bungling. He inexplicably chose the division to lead the assault by lot, he failed to clear the ground in front of the lead brigades, and -- in a repeat of Fredericksburg -- he fed regiment after regiment into the death trap of the crater Burnside went on leave and was never recalled. He eventually resigned on April 15, 1865. He became the governor of Rhode Island for 3 years, and a senator for that state until his death in 1881.
Burnside's most lasting legacy is not a failure, or a defeat, but his personal appearance. His side whiskers resulted in the term "sideburns". It's a strange legacy for a man who once commanded an army, who had held so much promise but often failed to live up to it.