After being on duty in Jackson until 9 February 1863, the 114th Illinois moved to Memphis where it guarded the Memphis and Charleston Railroad. On 17 March the regiment boarded river transports at Memphis and traveled down the Mississippi River to Young's Point, Louisiana, arriving on 2 April. The unit camped at Duckport, Louisiana, until 2 May when it joined the Vicksburg campaign. During the campaign, the 114th Illinois under Colonel Judy was in Brigadier General Ralph Pomeroy Buckland's and (later) Colonel William L. McMillen's 1st Brigade, Brigadier General James M. Tuttle's 3rd Division, Major General William Tecumseh Sherman's XV Corps, Grant's Army of the Tennessee. The regiment marched from Grand Gulf to Jackson, Mississippi on 2–14 May. It fought in the Battle of Jackson on 14 May, sustaining losses of 5 men killed and wounded. The Siege of Vicksburg cost the unit 20 men killed and wounded. During the successful siege, which ended on 4 July, the regiment participated in an expedition to Mechanicsburg from 26 May to 4 June.