On 20 September 1861, the 33rd Illinois Infantry moved to Ironton, Missouri, where it was based until March 1862. During this period, the regiment was attached to the Department of Missouri and took part in an expedition which resulted a skirmish at Big River Bridge near Potosi on 15 October and the Engagement at Fredericktown on 21 October. The men became hardened to warfare by fights with Confederate partisans. In one struggle, Lippincott stabbed an enemy officer in the ribs with his sword and then, grabbing the Confederate's pistol, shot him in the back. The 33rd Illinois was assigned to the 2nd Brigade, Army of Southeast Missouri in March–May 1862. Under the overall command of Brigadier General Frederick Steele, the regiment marched to Batesville, Arkansas, on 5 April–3 May. At Batesville, Steele's column joined the Army of the Southwest under Major General Samuel Ryan Curtis and the 33rd Illinois was reassigned to the 1st Division in Curtis' army in May–July 1862.