Four Chicago Companies mustered into State service at Camp Yates May 4, 1861. Regiment organized at Chicago, Ill., and mustered in June 17, 1861. Moved to Quincy, Ill., July 12-13, 1861. Thence to Palmyra, Mo., July 14, and guard Hannibal and St. Jo. R. R. from Quincy to Palmyra and between Palmyra and Hannibal till July 27. Moved to Hannibal, thence to St. Louis, Mo., and to Bird's Point and Norfolk, Mo., and duty at Norfolk till August 14. Moved to Ironton, Mo., August 14. Attached to Department of Missouri to September, 1861. Dept. of Kentucky to October, 1861. Elizabethtown, Ky., Dept. of the Cumberland, to November, 1861. 8th Brigade, Army of the Ohio, to December, 1861. 8th Brigade, 3rd Division, Army of the Ohio, to July, 1862. Unattached R. R. Guard, Army of the Ohio, to September, 1862. 29th Brigade, 8th Division, Army of the Ohio, to November, 1862. 2nd Brigade, 2nd Division, Centre 14th Army Corps, Army of the Cumberland, to January, 1863, 2nd Brigade, 2nd Division, 14th Army Corps, to October, 1863. 2nd Brigade, 1st Division, 14th Army Corps, October, 1863. 1st Brigade, 3rd Division, 14th Army Corps, to July, 1864.
SERVICE - Prentiss' Expedition toward Dallas and Jackson, Mo., August 29-September 8, 1861. Moved to Cape Girardeau, Fort Holt, Ky., and Elliott's Mills, thence moved to Cairo, Ill., September 16, under orders for Washington, D.C. While en route East, September 17, via Ohio & Mississippi R. R., bridge No. 48, over Beaver Creek, 30 miles west of Cincinnati, Ohio, broke through, precipitating six passenger coaches a distance of 60 feet, killing and wounding 129 of the Regiment. At Camp Dennison, Ohio, till September 24. Moved to Louisville, Ky., September 24-25, thence to Lebanon, Ky., September 25, and duty there till October 22. Moved to Elizabethtown, Ky., October 22, and duty there and at Bacon Creek till February 10, 1862. Advance on Bowling Green, Ky., February 10-15. Occupation of Bowling Green February 15, thence advance to Nashville, Tenn., February 22-25. Occupation of Nashville February 25 to March 18. Advance to Murfreesboro, Tenn., March 18, thence to Shelbyville, Tullahoma and McMinnville March 25-28. Advance on Huntsville, Ala., via Fayetteville April 4-11. Occupation of Huntsville April 11. Advance on and capture of Decatur and Tuscumbia, Ala., April 11-14. Action at Tuscumbia April 24. Athens May 13. At Huntsville till May 26. Moved to Fayetteville May 26-June 2. Negley's Expedition to Chattanooga, Tenn., June 2-10. Chattanooga June 7-8. Expedition to Larkinsville and Stevenson, Ala., June 14-20. Winchester June 16. Guard R. R. and bridges from Huntsville to Decatur till August. Richland Creek, near Pulaski, August 27. Retreat to Nashville, Tenn., August 27-29. Siege of Nashville September 5-November 6. Repulse of Forest's attack on Edgefield November 5. At Nashville till December 26. Advance on Murfreesboro, Tenn., December 26-30. Battle of Stone River December 30-31, 1862, and January 1-3, 1863. At Murfreesboro till June. Middle Tennessee (or Tullahoma Campaign) June 24-July 7. Occupation of Middle Tennessee till August 16. Passage of Cumberland Mountains and Tennessee River and Chickamauga, Ga., Campaign August 16-September 22. Davis' Cross Roads, Ga., September 11. Battle of Chickamauga, Ga., September 18-21. Rossville Gap September 21. Siege of Chattanooga September 24-November 23. Chattanooga-Ringgold Campaign November 23-27. Orchard Knob November 23-24. Mission Ridge November 25. Pursuit to Ringgold, Ga., November 26-27. Pea Vine Valley and Graysville November 26. At Chattanooga till February 22, 1864. Demonstration on Dalton, Ga., February 22-27. Tunnel Hill, Buzzard's Roost Gap and Rocky Faced Ridge February 23-25. At Graysville till May 3. Atlanta (Ga.) Campaign May 3-June 8. Demonstration on Rocky Faced Ridge May 8-11. Battle of Resaca May 14-15. Kingston May 18-19. Advance on Dallas May 22-25. Operations on line of Pumpkin Vine Creek and battles about Dallas, New Hope Church and Allatoona Hills May 25-June 5. At Ackworth, Ga., till June 8. Moved to Chicago June 8-17.
Mustered out July 9, 1864; expiration of term.
Regiment lost during service 4 Officers and 60 Enlisted men killed and mortally wounded and 4 Officers and 101 Enlisted men by disease. Total 169.