 Participation in Grant's Vicksburg Campaign followed, with the 4th Minnesota fighting in the Battle of Port Gibson on May 1, 1863, the Battle of Raymond on May 12, the Battle of Jackson on May 14, the Battle of Champion's Hill May 16, the Battle of Big Black River on May 17 and the Siege of Vicksburg from May 18 to July 4, 1863.The regiment performed garrison duty at Vicksburg followed the surrender, remaining at that location until September 12, 1863.The regiment participated in the Third Battle of Chattanooga from November 23–27 1863, then was on garrison duty at Bridgeport and Huntsville in Alabama, until June 1864, having Veteranized during the spring of 1864.