Organized at St. Charles, Ills., and mustered in September 18, 1861. Moved to Washington, D.C., October 13-17. At Meridian Hill until December 17 and at Alexandria, Va., until March, 1862. Attached to Sumner's Division, Army of the Potomac, December, 1861, to March, 1862, Cavalry 2nd Army Corps, Army of the Potomac, to May, 1862. Stoneman's Light Brigade to June, 1862. Averill's Cavalry Brigade, 5th Army Corps, to July, 1862. 2nd Brigade, Stoneman's Cavalry Division, Army of the Potomac, to September, 1862. 1st Brigade, Pleasanton's Cavalry Division, Army of the Potomac, until February, 1863. 1st Brigade, 1st Division Cavalry Corps, Army of the Potomac, to April, 1864. 2nd Brigade, 3rd Division Cavalry Corps, Army Potomac, to June, 1864 (Detachment). Regiment Unattached Defenses of Washington, D.C., 22nd Army Corps, to November, 1864. 1st Separate Brigade, 22nd Army Corps, Department of Washington, to July, 1865.

SERVICE - Advance on Manassas, Va., March 10-19, 1862. Reconnaissance to Gainesville March 20. Operations on the Orange and Alexandria R. R. March 28-29. Warrenton Junction March 28. Bealeton Station March 28. Rappahannock Station March 29. Reconnaissance to the Rappahannock April 2. Moved to the Peninsula, Virginia, April 23-May 1. Near Williamsburg May 4. Battle of Williamsburg May 5. Mechanicsville May 23-24. Battle of Fair Oaks, Seven Pines, May 31-June 1. Seven days before Richmond June 25-July 1. Ashland June 25 (Detachment). Mechanicsville, Atlee's Station and near Hanover Court House, June 26. Hundley's Corners June 26-27. Garnett's Farm and Gaines' Mill June 27. Despatch Station June 28 (Cos. "E," "K"). Savage Station June 29. White Oak Swamp and Glendale June 30. Malvern Hill July 1. Reconnaissance from Harrison's Landing July 4. At Harrison's Landing until August 16. Malvern Hill July 5. Expedition to Malvern Hill July 20-22. Malvern Hill August 5. Movement to Fortress Monroe, thence to Alexandria August 16-23. Falls Church September 3-4. Poolesville, Md., September 7-8. Barnesville September 9. Monocacy Church and Nolansville September 9. Middletown September 10. Sugar Loaf Mountain September 11-12. Frederick September 12. Middletown September 13. Catoctin Mountain September 13. South Mountain September 14. Boonesborough September 15. Antietam September 16-17. Shephardstown Ford September 19. Reconnaissance from Sharpsburg to Shepardstown, W. Va., October 1. Martinsburg October 1. Pursuit of Stuart into Pennsylvania October 9-12. Mouth of Monocacy October 12. Sharpsburg and Hagerstown Pike October 16-17. Purcellsville and near Upperville October 29 (Detachment). Snickersville October 31. Philomont November 1-2. Upperville November 2-3. Union November 3. Barber's Cross Roads, Chester Gap and Markham November 5-6. Sperryville November 7. Little Washington November 8. Markham Station and Barber's Cross Roads November 10. Battle of Fredericksburg, Va., December 12-15. Turner's Mills January 30, 1863. Operations in Westmoreland and Richmond Counties February 10-16. Near Dumfries March 15 and 29. Zoar Church March 30. Chancellorsville Campaign April 27-May 8. Stoneman's Raid April 29-May 8. Rapidan Station May 1. Warrenton May 6. Lancaster May 20-21. Clendennin's Raid below Fredericksburg May 20-28. Brandy Station and Beverly Ford June 9. Aldie June 17. Goose Creek June 18. Upperville June 21. Battle of Gettysburg, Pa., July 1-3. Williamsport July 6-7. Funkstown, Md., July 8. Boonesborough July 8. Chester Gap and Benevola or Beaver Creek, July 9. At and near Funkstown, Md., July 10-13. Falling Waters July 15. Chester Gap July 21-22. Lovettsville July 22. Kelly's Ford July 31-August 1. Near Culpeper August 1-3. Brandy Station August 4. Weaversville August 27. Brandy Station September 8. Raccoon Ford and Stevensburg September 10-11. Culpeper and Pony Mountain September 13. Reconnaissance across the Rapidan September 21-23. Liberty Mills September 21. Jack's Shop, Madison Court House, September 22. Mitchell's Ford October 7. Bristoe Campaign October 9-22. Culpeper October 9. Raccoon Ford October 10. Morton's Ford October 10. Stevensburg, near Kelly's Ford and Brandy Station, October 11. Fleetwood or Brandy Station October 12. Oak Hill October 15. Madison Court House October 16. Hazel River October 17. Bealeton October 27. Near Catlett's Station October 30. Advance to line of the Rappahannock November 7-8. Warrenton or Sulphur Springs, Jeffersonton and Hazel River November 8. Mine Run Campaign November 26-December 2. Parker's Store November 29. Jennings' Farm, near Ely's Ford, December 1. Reconnaissance to Madison Court House January 31, 1864 (Detachment). Veterans on furlough January to March, 1864. Camp at Giesboro Point until May. Patrol duty at Washington, D.C., and scout duty at Fairfax, Va., until April, 1865, having numerous engagements with Mosby's guerrillas and the Black Horse Cavalry. A detachment with Army of the Potomac and participated in the Rapidan Campaign May-June, 1864. Craig's Meeting House, Va., May 5. Todd's Tavern May 5-6. Alsop's Farm May 8. Guinea Station May 18. Salem Church and Pole Cat Creek May 27. Cold Harbor June 1-12. Point of Rocks, Md., July 5. Noland's Ferry July 5. Middletown and Solomon's Gap July 7. Frederick July 7. Frederick July 8, (Detachment). Battle of Monocacy July 9. Rockville and Urbana July 9. Near Fort Stevens, D.C., July 11. Along northern defenses of Washington, D.C., July 11-12. Rockville July 13. Cockeyville July 18. Philomont July 20. Snickersville July 21. Monocacy Junction July 30. Near Piedmont October 9. Near Rectortown October 10. White Plains October 11. Upperville October 28 (Detachment). Operations at Snicker's Gap October 28-29 (Detachment). Manassas Junction November 11. Fairfax Station November 26. Scout from Fairfax Court House to Hopewell Gap December 26-27. Scout from Fairfax Court House to Brentsville February 6-7, 1865, and to Aldie and Middleburg February 15-16 (Co. "B"). Operations about Warrenton, Bealeton Station, Sulphur Springs and Centreville March 3-8. Duty about Washington, D.C., until July. Ordered to St. Louis, Mo., thence to Chicago, Ill., and mustered out July 17, 1865.

Regiment lost during service 7 Officers and 68 Enlisted men killed and mortally wounded and 1 Officer and 174 Enlisted men by disease. Total 250.