125th Illinois Infantry Regiment

The 125th Illinois Volunteer Infantry was an infantry regiment in the Union Army during the American Civil War.

Service
The 125th Illinois Infantry was organized at Danville, Illinois, and mustered in for three years service on September 3, 1862, under the command of Colonel Oscar Fitzalan Harmon.

The regiment was attached to 36th Brigade, 11th Division, Army of the Ohio, to October 1862. 36th Brigade, 11th Division, III Corps, Army of the Ohio, to November 1862. 2nd Brigade, 4th Division, Centre, XIV Corps, Army of the Cumberland, to January 1863. 2nd Brigade, 4th Division, XIV Corps, to June 1863. 2nd Brigade, 2nd Division, Reserve Corps, Army of the Cumberland, to October 1863. 3rd Brigade. 2nd Division, XIV Corps, Army of the Cumberland and Army of Georgia, to June 1865.

The 125th Illinois Infantry mustered out of service on June 9, 1865.

Detailed service
Moved to Covington, Ky., September 25, 1862. Pursuit of Bragg into Kentucky October 1–16, 1862. Battle of Perryville, Ky., October 8. March to Nashville, Tenn., October 16-November 7, and duty at Nashville until June 30, 1863. Moved to Murfreesboro, Tenn.. June 30. Return to Nashville July 18 and duty there until August 20. Moved to Chattanooga. Tenn., via Brentwood, Columbia, Huntsville, Ala.. and Bridgeport, Ala., August 20-September 16. Battle of Chickamauga, September 19–21. Siege of Chattanooga, Tenn., September 24-November 23. Ringgold September 26. Chattanooga-Ringgold Campaign November 23–27. Orchard Knob November 23. Tunnel Hill November 24–25. Missionary Ridge November 25. Pursuit to Graysville November 26–27. March to relief of Knoxville, Tenn.. November 28-December 17. At Lee and Gordon's Mills until May 1864. Demonstration on Dalton, Ga., February 22–27, 1864. Tunnel Hill, Buzzard's Roost Gap and Rocky Faced Ridge February 23–25. Atlanta Campaign May 1-September 8. Tunnel Hill May 6–7. Demonstration on Rocky Faced Ridge May 8–11. Buzzard's Roost Gap May 8–9. Battle of Resaca May 14–15. Rome May 17–18. 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 Kennesaw Mountain June 10-July 2. Pine Hill June 11–14. Lost Mountain June 15–17. Assault on Kennesaw 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. Utoy Creek August 5–7. Flank movement on Jonesboro August 25–30. Battle of Jonesboro August 31-September 1. Lovejoy's Station September 2–6. Operations against Hood and Forest in northern Georgia and northern Alabama September 29-November 3. March to the sea November 15-December 10. Louisville November 30. Cuyler's Plantation December 9. Siege of Savannah December 10–21. Campaign of the Carolinas January to April 1865. Averysboro, Taylor's Hole Creek, N. C., March 16. Battle of Bentonville March 19–21. Occupation of Goldsboro March 24. Advance on Raleigh April 10–14. Occupation of Raleigh April 14. Bennett's House April 26. Surrender of Johnston and his army. March to Washington, D.C., via Richmond, Va., April 29-May 19. Grand Review of the Armies May 24.

Casualties
The regiment lost a total of 204 men during service; 9 officers and 88 enlisted men killed or mortally wounded, 3 officers and 104 enlisted men died of disease.

Commanders

 * Colonel Oscar Fitzalan Harmon - killed in action at the battle of Kennesaw Mountain
 * Colonel James Weston Langley - promoted from lieutenant colonel, but never mustered