In the Little Rock campaign from late August to early September, the regiment unsuccessfully attempted to defend the city from a Union attack, suffering light casualties at the Battles of Brownsville, Bayou Meto, and Bayou Fourche. During the 25 October Battle of Pine Bluff, it dismounted and attacked the Pine Bluff Union garrison from the south, but was repulsed after an intense action, suffering casualties of three killed and seven wounded. Shortly afterwards, the 3rd Missouri Cavalry moved into winter quarters in southern Arkansas, where it passed the next several months uneventfully. Lieutenant Colonel Campbell died on 19 November; he was replaced by Major Leonidas A. Campbell, who was promoted to Lieutenant Colonel on 30 December. Company B Captain James Surridge simultaneously replaced Campbell as Major.