While winter was typically the time for major armies to enter winter encampments and train for the spring campaign season, there are some notable exceptions.

The two largest winter battles both occurred at the end of 1862. Fredericksburg, a tactical disaster for the Army of the Potomac, was fought between December 11 and December 15, 1862 between Lee’s Army of Northern Virginia and the Army of the Potomac under Ambrose Burnside. The weather didn’t impact the initial campaign and the battle too heavily, though it was notably frigid. The retreat, however, turned into a memorable quagmire, due to driving rains and ice. It became known as the “Mud March.”

The Battle of Stones River was fought between December 31 and January 2, 1862-63. Fought between William Rosecrans’ Army of the Cumberland and Braxton Bragg’s Army of Tennessee, this battle was a tactical draw, but the withdrawal of Bragg out of middle Tennessee meant the Union could claim a strategic victory. In terms of relative casualties, this battle was the bloodiest of the war. Around 32% of the combatants were killed, wounded, or missing by the end. To put that in perspective, a modern military unit with 20% casualties is considered combat ineffective.

There were other battles fought in winter. The Battle of Nashville was fought at the very end of fall, on December 15-16, 1864. Overall, though, winter battles had little strategic impact because maneuver after the battle was limited by weather and supplies. Fredericksburg was a disaster for the Union, but Lee couldn’t follow up the victory. Stones River was a strategic Union victory, but it took until Spring before Rosecrans started to follow up and begin to maneuver against Bragg.

Even aggressive generals like Grant and Lee were restricted by poor roads. Winter did offer a good opportunity to rest and retrain.