At the Battle of Grand Gulf on April 29, 1863, the battery was stationed at a point away from Fort Wade on the Big Black River. At the Battle of Champion Hill on May 16, the battery was in the brigade of Brigadier General Martin E. Green. After fighting at Champion Hill, the battery lost its cannons at the Battle of Big Black River Bridge on May 17; after which it entered the defenses of Vicksburg, Mississippi. The battery was present during the Siege of Vicksburg and was captured when the Confederate garrison surrendered on July 4. The 64 surviving men of the battery were paroled and exchanged and reported to Demopolis, Alabama. On October 3, the 3rd Missouri Light Battery was consolidated with the Jackson Missouri Battery and assigned to Brigadier General John C. Moore's brigade. The combined battery was generally treated as a continuation of the 3rd Light Battery. At the Battle of Missionary Ridge on November 25, the battery was available, but did not see action; replacement cannons for those lost at Big Black River Bridge had not yet arrived. After Missionary Ridge, the battery was stationed at Meridian, Mississippi and then Mobile, Alabama.