Organized August 9 to October 8, 1861, by order of War Department. Regiment designated 7th United States Cavalry October 26, 1861. This being in excess of number provided for by Act of Congress, Regiment was designated 2nd New York Volunteer Cavalry or "Harris Light Cavalry."
Left New York for Washington, D. C., September 18, 1861. Attached to McDowell's Division, Army of the Potomac, to March, 1862. King's 3rd Division, 1st Army Corps, Army of the Potomac, and Department of the Rappahannock, to June, 1862. Bayard's Cavalry Brigade, 3rd Corps, Army of Virginia, to September, 1862. Bayard's Cavalry Brigade, Army of the Potomac, to December 15, 1862. (Cos. "A," "B," "I" and "K" with 3rd Division, 1st Army Corps, Army of the Potomac, September and October, 1862.) Gregg's Cavalry Brigade, Army of the Potomac, to February 11, 1863. 1st Brigade, 3rd Division, Cavalry Corps, Army of the Potomac, to June 14, 1863. (A Battalion at Yorktown, Va., Unattached, 4th Army Corps, Dept. of Virginia, June, 1863. 1st Brigade, 1st Division, 4th Army Corps, Dept. of Virginia, to July, 1863. King's Division, 22nd Army Corps, to August, 1863.) 2nd Brigade, 2nd Division, Cavalry Corps, Army of the Potomac, to August 12, 1863. 1st Brigade, 3rd Division, Cavalry Corps, to August, 1864. 1st Brigade, 3rd Division, Cavalry Corps, Army of the Shenandoah, Middle Military Division, to March, 1865, and Army of the Potomac, to June, 1865.

SERVICE:
Duty in the Defences of Washington, D. C., till March, 1862. Advance on Manassas, Va., March 10-16. Advance on Falmouth, Va., April 3-18. Falmouth April 17 and 19. Near Fredericksburg May 5. Bowling Green Road May 11. Flipper's Orchard July 4. Expedition from Fredericksburg to Hanover Junction July 19-20. Beaver Dam Station July 20. Reconnoissance to James City July 22-24. Mt. Carmel Church July 23. Expedition to Frederick's Hall Station August 5-8. Thornburg or Massaponax Church August 5-6. Orange Court House August 8. Battle of Cedar Mountain August 9. Pope's Campaign in Northern Virginia August 16-September 2. Near Rapidan Station August 18. Brandy Station August 20. Fords of the Rappahannock August 21-23. Kelly's Ford August 21. Catlett's Station August 22. Culpeper August 23. Waterloo Bridge August 23. Sulphur Springs August 24. Manassas Junction August 26. Thoroughfare Gap August 28. Groveton August 29. Bull Run August 30. Germantown August 31. Centreville and Chantilly August 31. Little River Turnpike September 1. South Mountain, Md., September 14. Goose Creek September 17. Reconnoissance to Leesburg September 16-19 (6 Cos.). Action at Leesburg September 17. Warrenton September 29. Dumfries October 5. Hazel River October 7. Aldie and Mountsville October 31. Sudley Church November 3. New Baltimore, Salem, Warrenton and Upperville November 4. Rappahannock Station November 8-9. Aldie November 25. Stafford Court House December 7. Fredericksburg December 12-15. Rappahannock Station April 14, 1863. Warrenton April 16. Rappanannock Station April 19. Stoneman's Raid April 27-May 8. Louisa Court House May 2. Ashland and Hanover Station May 3. Glen Allen May 4. Aylett's May 5. King and Queen Court House May 6. Centreville May 6. Morrisville May 10. Expedition from Gloucester into Matthews County May 19-20 (Detachment). Falmouth June 1. Brandy Station June 3. Beverly Ford and Brandy Station June 9. Aldie June 17. Middleburg June 19. Uppervllle June 21. Rockville, Md., June 28. (Dix's Peninsula Campaign June 24-July 7, Battalion.) Cooksville June 29. Battle of Gettysburg, Pa., July 1-3. Monterey Gap July 4. Smithburg July 5. Emmettsburg July 5. Hagerstown and Williamsport July 6. Boonsborough July 8. Funkstown July 9. Jones' Cross Roads July 10-13. Hagerstown July 11-13. Williamsport July 14. Falling Waters July 14. Berryville July 16. Bristerburg July 27. Fairfax August 3. Thoroughfare Gap August 5. Near Aldie August 12-14. U. S. Ford August 22. Expedition to Port Conway September 1-3. Lamb's Creek September 1. Advance from the Rappahannook to the Rapidan September 13-17. Culpeper Court House September 13. Somerville Ford September 14. Robertson's Ford September 16. U. S. Ford September 17. Culpeper September 19. Madison Court House September 21. White's Ford and Liberty Mills September 21-22. Scout to Hazel River September 27-28. Hazel Run October 2. Hazel River October 6. Culpeper October 7. Bristoe Campaign October 9-22. James City, Robertson's River and Bethesda Church October 10. Near Culpeper October 11. Brandy Station October 11-12. Gainesville October 14. Groveton October 17-18. Haymarket, Buckland's Mills and New Baltimore October 19. Catlett's Station November 4. Advance to line of the Rappahannock November 7-8. Stevensburg November 7. Hartwood Church November 15. Germania Ford November 18. Mine Run Campaign November 26-December 2. Morton's Ford November 26. New Hope Church November 27. Robertson's Tavern November 29. Germania Ford December 2. Raccoon Ford December 5. Somerville December 18. Kelly's Ford January 12, 1864. Ellis Ford January 17. Stevensburg January 19. Ely's Ford January 19. Kilpatrick's Raid to Richmond February 28-March 3. Beaver Dam and Frederick's Hall Station and South Anna Bridge February 29. Defences of Richmond March 1. Old Church and King and Queen March 2. Near Walkertown March 2 (Detachment, Dahlgren killed). Near Tunstall Station March 3 (Detachment). New Kent Court House and Stevensville March 3. Carrollton's Store March 11. Rapidan Campaign May-June. Craig's Meeting House May 5. Todd's Tavern May 5-6. Wilderness May 6-7. Alsop's Farm, Spottsylvania, May 8. Sheridan's Raid to James River May 9-24. North Anna River May 9-10. Ground Squirrel Church and Yellow Tavern May 11. Brooks' Church or fortifications of Richmond May 12. Strawberry Hill May 12. Polecat Station May 23. Demonstration on Little River May 26. Totopotomoy May 28-31. Hanover Court House May 29-30. Mechump's Creek May 31. Cold Harbor June 1-12. Totopotomoy and Gaines' Mill June 2. Haw's Shop June 3. Via's House June 3. Old Church June 10-11. Bethesda June 11. Riddell's Shop and Long Bridge June 12. Malvern Hill June 14. Smith's Store near St. Mary's Church June 15. Wilson's Raid to south side and Danville Railroad June 22-30. Black and White Station and Nottoway Court House June 23. Sapponay Church or Stony Creek June 28. Ream's Station June 29-30 and July 3. Sheridan's Shenandoah Valley Campaign August 7-November 28. Near Winchester August 17. Summit Point, Charlestown, August 21. Near Kearneysville August 25. Waynesboro September 2. Berryville September 4. Near Winchester September 9. Abram's Creek September 13. Battle of Opequan, Winchester, September 19. Near Cedarville September 20. Fisher's Hill September 21. Front Royal Pike September 21. Milford September 22. Staunton September 26. Waynesboro September 29. Mt. Crawford September 30. Bridgewater and Woodstock October 2. Brock's Gap October 6. New Market October 7. Fisher's Hill October 8. Tom's Brook, "Woodstock Races," October 8-9. Cedar Run October 13. Battle of Cedar Creek October 19 and November 7. Nineveh November 12. Mt. Jackson November 22. Hood's Hill November 23. Expedition from Kernstown to Moorefield November 28-December 2. Moorefield December 3. Expedition to Lacy Springs December 19-22. Lacy Springs December 21. Mt. Jackson December 21. Sheridan's Raid from Winchester February 27-March 25, 1865. Occupation of Staunton March 2. Action at Waynesboro March 2. Charlottesville March 3. Ashland March 15. Appomattox Campaign March 28-April 9. Dinwiddie Court House March 30-31. Five Forks April 1. Fall of Petersburg April 2. Namozine Church April 3. Sailor's Creek April 6. Appomattox Station April 8. Appomattox Court House April 9. Surrender of Lee and his army. Expedition to Danville April 23-29. March to Washington, D. C., May. Grand Review May 23. Mustered out June 5 and honorably discharged from service June 23, 1865.
Regiment lost during service 9 Officers and 112 Enlisted men killed and mortally wounded and 1 Officer and 235 Eniisted men by disease. Total 357.