Organized at St. Louis, Mo., as 9th Missouri Infantry, September 18, 1861 (Cos. "A," "B," "C" at Cape Girardeau from August 6, 1861). Regiment moved to Jefferson Barracks, Mo., September 21, 1861; thence to Booneville, Mo., September 30. Attached to Kelton's Brigade, Pope's Division, Fremont's Army of the West, to November, 1861. Department of Missouri to February, 1862. (Designation of Regiment changed to 59th Illinois Infantry February 12, 1862.) 2nd Brigade, 3rd Division, Army of Southwest Missouri, to June, 1862. 1st Brigade, 4th Division, Army of Mississippi, to September, 1862. 30th Brigade, 9th Division, Army of the Ohio, to October, 1862. 30th Brigade, 9th Division, 3rd Corps, Army of the Ohio, to November, 1862. 1st Brigade, 1st Division, Right Wing 14th Army Corps, Army of the Cumberland, to January, 1863. 1st Brigade, 1st Division, 20th Army Corps, Army of the Cumberland, to October, 1863. 2d Brigade, 1st Division, 4th Corps, October, 1863. 3rd Brigade, 1st Division, 4th Army Corps, to May 1864. 2nd Brigade, 1st Division, 4th Army Corps, to August, 1864. 3rd Brigade, 1st Division, 4th Army Corps, August, 1864. 2nd Brigade, 3rd Division, 4th Army Corps, to August, 1865. Department of Texas to December, 1865.

SERVICE:
Fremont's advance on Springfield, Mo., October 13-November 3, 1861. March to Syracuse November 9-17, thence to LaMine River December 7 and to Georgetown, Mo., December 15. To LaMine Bridge December 23 and duty there till January 25, 1862. Curtis' advance on Springfield, Mo., January 25-February 11. Campaign against Price February and March. Battles of Pea Ridge, Ark., March 6-8. March to Sugar Creek March 10, thence to Cross Timbers. March to Batesville April 5-May 3. Moved to Cape Girardeau, Mo., thence to Pittsburg Landing, Tenn., May 11-24. Advance on and siege of Corinth, Miss., May 26-30. Pursuit to Booneville June 1-16. Duty at Jacinto, Miss., till August 4. Reconnoissance to Bay Springs, Miss., August 4-7. Bay Springs August 5. March to Murfreesboro, Tenn., August 8-September 1, thence to Louisville, Ky., in pursuit of Bragg, September 3-26. Pursuit of Bragg into Kentucky October 1-15. Battle of Perryville, Ky., October 8. Lancaster October 15. March to Nashville, Tenn., October 17-November 7 and duty there till December 26. Wilson's Creek Pike December 25. Advance on Murfreesboro, Tenn., December 26-30. Nolensville, Knob Gap, November 26. Triune December 27. Battle of Stone's River December 30-31, 1862, and January 1-3, 1863. At Murfreesboro till June. Reconnoissance to Versailles March 9-14. Operations on Edgeville Pike June 4. Middle Tennessee or Tullahoma Campaign June 24-July 7. Liberty Gap June 24-27. Occupation of Middle Tennessee till August 16. Passage of the Cumberland Mountains and Tennessee River and Chickamauga (Ga.) Campaign August 16-September 22. Guard supply trains over Mountain in rear of Bragg's army during battle of Chickamauga. Siege of Chattanooga, Tenn., September 24-October 27. Reopening Tennessee River October 26-29. Chattanooga-Ringgold Campaign November 23-27. Battles of Lookout Mountain November 23-24. Mission Ridge November 25. Taylor's Ridge, Ringgold Gap, November 27. At Whiteside, Ala., till January 27, 1864. Regiment veteranize January 12, 1864. Veterans on furlough January 27-March 19. Moved to Cleveland, Tenn., and duty there till May. Atlanta (Ga.) Campaign May 1 to September 8, 1864. Tunnel Hill May 6-7. Demonstration on Rocky Faced Ridge May 8-11. Buzzard's Roost Gap May 8-9. Demonstration against Dalton May 9-13. Battle of Resaca May 14-15. Near Kingston May 18-19. Near Cassville May 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. Operations about Marietta and against Kenesaw Mountain June 10-July 2. Pine Hill June 11-14. Lost Mountain June 15-17. Assault on Kenesaw June 27. Ruff's Station, Smyrna Camp Ground, July 4. Chattahoochie River July 5-17. Peach Tree Creek July 19-20. Siege of Atlanta July 22-August 25. Flank movement on Jonesboro August 25-30. Red Oak August 28-29. Rough and Ready August 31. Battle of Jonesboro August 31-September 1. Lovejoy Station September 2-6. Pursuit of Hood, into Alabama, October 3-26. Nashville Campaign November-December. Columbia, Duck River, November 24-27. Battle of Franklin November 30. Battle of Nashville December 15-16. Pursuit of Hood, to the Tennessee River, December 17-28. Moved to Huntsville, Ala., and duty there till March, 1865. Expedition to Bull's Gap and operations in East Tennessee March 15-April 22. At Nashville, Tenn., till June. Moved to New Orleans, La., June 16, thence to Indianola, Texas, July 7. Duty at San Antonio and at New Braunfels, Texas, till December. Mustered out December 8, 1865.

Regiment lost during service 4 Officers and 105 Enlisted men killed and mortally wounded and 4 Officers and 117 Enlisted men by disease. Total 230.