Organized at Burlington July 15, 1861. Moved to Keokuk, Iowa, August 2, thence to St. Louis, Mo., August 11. Attached to Fremont's Army of the West and Dept. of Missouri, to March, 1862. 1st Brigade, 2nd Division, Army Mississippi, to April, 1862. 2nd Brigade, 3rd Division, Army Mississippi, April, 1862. 1st Brigade, 3rd Division, Army Mississippi, to November, 1862. 3rd Brigade, 7th Division, Left Wing 13th Army Corps (Old), Dept. Tennessee, to December, 1862. 3rd Brigade, 7th Division, 16th Army Corps, to January, 1863. 3rd Brigade, 7th Division, 17th Army Corps, to September, 1863. 3rd Brigade, 2nd Division, 17th Army Corps, to December, 1863. 3rd Brigade, 3rd Division, 15th Army Corps, to August, 1864.
Expedition to Northeastern Missouri August, 1861. Detachment moved to St. Louis, Mo., August 11, thence to Jefferson City, Mo., August 14. Expedition toward Columbia September 2. Moved to Booneville September 14, thence to Glasgow September 25. Return to Booneville October 2. Fremont's Campaign against Springfield, Mo., October 4-November 8. Guard railroad and duty at Booneville and Syracuse till February, 1862. Moved to Cairo, Ill., February 6, thence to Benton, Mo. Operations against New Madrid, Mo., February 28-March 15, and against Island No. 10, March 15-April 8. Expedition to Fort Pillow April 13-17. Moved to Hamburg Landing, Tenn., April 18-22. Advance on and siege of Corinth, Miss., April 29-May 30. Pursuit to Booneville May 31-June 6. At Clear Creek till August 5. Expedition to Holly Springs June 27-July 10. Moved to Jacinto August 5. March to Iuka September 18-19. Battle of Iuka September 19. Moved to Corinth October 1. Battle of Corinth October 3-4. Pursuit to Ripley October 5-12. Grant's Central Mississippi Campaign November, 1862, to January, 1863. Reconnoissance from LaGrange November 8-9, 1862. Duty at Memphis, Tenn., January to March, 1863. Expedition up Yazoo and operations about Fort Pemberton and Greenwood March 13-April 5. Fort Pemberton March 25. Moved to Milliken's Bend, La., April 13. Movement on Bruinsburg and turning Grand Gulf April 25-30. Battle of Port Gibson May 1. South Fork Bayou Pierrie May 2. Battles of Raymond May 12. Near Raymond May 13. Jackson May 14.
Champion's Hill May 16. Siege of Vicksburg May 18-July 4. Assaults on Vicksburg May 19 and 22. Surrender of Vicksburg July 4. Duty at Vicksburg till September 13. Moved to Memphis, thence march to Chattanooga, Tenn., September 13-November 20. Operations on Memphis & Charleston railroad in Alabama October 20-29. Battles of Chattanooga November 23-25. Tunnel Hill November 24-25. Mission Ridge, November 25. Pursuit to Graysville November 26-27. March to relief of Knoxville November 28-December 17. Duty at Bridgeport and Huntsville, Ala., till April, 1864. Veterans on furlough April-May. Non-Veterans guard railroad till June 15. Mustered out July 30. Moved to Huntsville, thence to Kingston, Ga., June 23. Guard duty there and at Etowah River till July 30. Consolidated with 5th Iowa Cavalry August 8, 1864.
Regiment lost during service 9 Officers and 108 Enlisted men killed and mortally wounded and 2 Officers and 131 Enlisted men by disease. Total 250.