Seeking to redeem his reputation after the disaster at Fredericksburg, Union commander Ambrose Burnside launched a flanking march up the Rappahannock River. Days of relentless rain turned the roads into thick mud, swallowing wagons, artillery, and horses, and the offensive collapsed before a single shot was fired at the enemy, further eroding confidence in Burnside's leadership.
Soldiers who had endured the slaughter at Fredericksburg six weeks earlier were in no mood for another Burnside gambit, and the weather seemed to conspire against him from the start. Rain began almost as soon as the march began and did not let up, turning Virginia's clay roads into a viscous, sucking mud that some veterans swore was deeper than any they'd seen.
Men and mules alike became stuck fast; teams of a dozen horses could not budge single wagons. Soldiers joked bitterly that they were fighting the mud, not the Confederates, and photographs and sketches from the campaign show artillery pieces buried nearly to their axles.
Burnside called off the operation after just a few days, humiliated. The 'Mud March' became a symbol of Union dysfunction that winter, and within days Burnside was relieved of command of the Army of the Potomac, replaced by Joseph Hooker.