12th United States Infantry

Organized by direction of the President May 4, 1861, and confirmed by Act of Congress July 29, 1861. Organized at Fort Hamilton, N.Y. Harbor. Moved to Washington, D.C., March 5, 1862. Attached to Sykes' Regular Infantry, Reserve Brigade, Army Potomac, to May, 1862. 1st Brigade, 2nd Division, 5th Army Corps, to August, 1863. Dept. of the East to September, 1863. 1st Brigade, 2nd Division, 5th Army Corps, to March, 1864. 4th Brigade, 1st Division, 5th Army Corps, to April, 1864. 1st Brigade, 1st Division, 5th Army Corps, to June, 1864. 1st Brigade, 2nd Division, 5th Army Corps, to November, 1864. Dept. of the East to July, 1865.

SERVICE. – Moved to the Virginia Peninsula March, 1862. Siege of Yorktown April 5-May 4. Seven days before Richmond June 25-July 1. Battles of Mechanicsville June 26; Gaines' Mill June 27; Turkey Bridge June 30; Malvern Hill July 1. At Harrison's Landing till August 16. Movement to Fortress Monroe, thence to Centreville August 16-28. Pope's Campaign in Northern Virginia August 28-September 2. Battles of Groveton August 29; Bull Run August 30. Maryland Campaign September 6-22. Battle of Antietam September 16-17. Shepherdstown Ford September 19-20. At Sharpsburg, Md., till October 29. Kearneysville and Shepherdstown October 16-17. Movement to Falmouth, Va., October 29-November 19. Battle of Fredericksburg, Va., December 12-15. "Mud March" January 20-24, 1863. Chancellorsville Campaign April 27-May 6. Battle of Chancellorsville May 1-5. Gettysburg (Pa.) Campaign June 11-July 24. Battle of Gettysburg, Pa., July 1-3. Pursuit of Lee July 5-24. Moved to New York August 16-19. (Cos. "F" and "H," 2nd Battalion, in N.Y. riots July, 1863.) Duty at New York till September 14. Rejoined army at Culpeper, Va., September 22. Bristoe Campaign October 9-22. Advance to line of the Rappahannock November 7-8. Mine Run Campaign November 26-December 2. Rapidan Campaign, battles of the Wilderness, May 5-7; Spottsylvania Court House May 8-21; North Anna River May 22-26. On line of the Pamunkey May 26-28. Totopotomoy May 28-31. Cold Harbor June 1-12. Bethesda Church June 1-3. Before Petersburg June 16-18. Siege of Petersburg June 16 to November 2. Mine Explosion, Petersburg, July 30 (Reserve). Weldon Railroad August 18-21. Poplar Springs Church, Peeble's Farm, September 29-October 2. Boydton Plank Road, Hatcher's Run, October 27-28. Moved to New York November 2-6. 1st Battalion on duty at Elmira, N.Y., and 2nd Battalion at Fort Hamilton. N.Y. Harbor, till July, 1865.

Regiment lost during service 8 Officers and 118 Enlisted men killed and mortally wounded and 3 Officers and 190 Enlisted men by disease. Total 319.

SOURCE: Frederick H. Dyer, A Compendium of the War of the Rebellion, Part 3, p. 1713