Over the winter of 1862–63, Sigel commanded the XI Corps, consisting primarily of German immigrant soldiers, in the Army of the Potomac. When Ambrose Burnside assumed command of the Army of the Potomac, he instituted 'grand divisions', consisting of two corps each; Sigel assumed command of the Reserve Grand Division, consisting of the XI and XII Corps. The Reserve Grand Division saw no action; it stayed in reserve during the Battle of Fredericksburg. After the battle, and the dissolution of the grand divisions, Sigel returned to command of the XI Corps. He had developed a reputation as an inept general, but his ability to recruit and motivate German immigrants kept him employed in a politically sensitive position. Many of these soldiers could speak little English beyond "I'm going to fight mit Sigel", which was their proud slogan and which became one of the favorite songs of the war.