The 100th New York Infantry Regiment was an infantry regiment in the Union Army during the American Civil War.
The 100th New York Infantry was organized at Buffalo, New York, and mustered in for three years service in January 1862 under the command of Colonel James M. Brown.
The regiment was attached to 1st Brigade, 3rd Division, IV Corps, Army of the Potomac, to June 1862. 1st Brigade, 2nd Division, IV Corps, to December 1862. Naglee's Brigade, Department of North Carolina, to January 1863. 2nd Brigade, 2nd Division, XVIII Corps, Department of North Carolina, to February 1863. 1st Brigade, 2nd Division, XVIII Corps, Department of the South, to April 1863. Folly Island, South Carolina, X Corps, Department of the South, to June 1863. 2nd Brigade, Folly Island, South Carolina, X Corps, to July 1863. 1st Brigade, Folly Island, South Carolina, X Corps, July 1863. 2nd Brigade, 1st Division, Morris Island, South Carolina, X Corps, July 1863. 3rd Brigade, Morris Island, South Carolina, X Corps, to November 1863. 2nd Brigade, Morris Island, South Carolina, X Corps, to January 1864. 2nd Brigade, Morris Island, South Carolina, Northern District, Department of the South, to April 1864. 2nd Brigade, 1st Division, X Corps, Army of the James, Department of Virginia and North Carolina, to May 1864. 3rd Brigade, 1st Division, X Corps, to December 1864. 3rd Brigade, 1st Division, XXIV Corps, to July 1865. 2nd Brigade, 1st Division, XXIV Corps, to August 1865.
The 100th New York Infantry mustered out of service on August 28, 1865.
Moved to New York City March 7, then to Washington, D.C., March 10, 1862. Ordered to the Virginia Peninsula March 28, 1862. Siege of Yorktown, April 5-May 4. Battle of Williamsburg, May 5. Operations about Bottom's Bridge May 20âÂÂ23. Reconnaissance to Seven Pines May 24âÂÂ27. Battle of Seven Pines, May 31-June 1. Seven Days Battles before Richmond June 25-July 1. Bottom's Bridge June 27âÂÂ29. White Oak Swamp June 30. Malvern Hill July 1. At Harrison's Landing until August 16. Moved to Fortress Monroe August 16âÂÂ22, then to Yorktown, Va., September 18. Duty at Yorktown and Gloucester Point until December 26. Reconnaissance to Gloucester and Matthews Counties December 11âÂÂ15. Skirmish at Wood's Cross Roads, Gloucester Court House, December 14. Moved to Beaufort, N.C., December 26, then to Port Royal, S.C., January 28âÂÂ31. Camp at St. Helena Island, S.C., February 12-March 23. Capture of Forts Wagner and Gregg September 7. until April 3. Action at Cole's Island March 31. Occupation of Folly Island, S.C.. April 5-July 10. Action at Folly Island April 10. Attack on Morris Island July 10. Assaults on Fort Wagner, Morris Island, S.C., July 11 and 18. Siege of Forts Wagner and Gregg, and operations against Fort Sumter and Charleston, July 18-September 7. Boat Expedition against Fort Gregg August 17. Bombardment of Fort Sumter August 17âÂÂ23. Capture of Forts Wagner and Gregg September 7. Duty on Morris Island and operations against Charleston until April 1864. Affair, Vincent's Creek, August 4, 1863. Moved to Gloucester Point. Va., April. Butler's operations on south side of the James River and against Petersburg and Richmond May 4âÂÂ28. Occupation of Bermuda Hundred May 5. Port Walthall Junction, Chester Station, May 7. Swift Creek May 8âÂÂ10. Operations against Fort Darling May 12âÂÂ16. Battle of Drury's Bluff May 14âÂÂ16. Bermuda Hundred May 16-June 20. Attacks on picket line May 21 and June 2 and 14. Port Walthall June 16âÂÂ17. Siege operations against Petersburg and Richmond June 16, 1864, to April 2, 1865. Action at Deep Bottom June 23. Groper House, Deep Bottom, July 21. Deep Bottom July 27âÂÂ28. Strawberry Plains, New Market Heights, August 14âÂÂ18. Moved to Petersburg front August 26, and duty there in trenches until September 27. Battle of Chaffin's Farm September 28âÂÂ30. Darbytown Road October 7. Reconnaissance to Darbytown Road October 13. Battle of Fair Oaks October 27âÂÂ28. Johnson's Farm October 29. Duty in trenches before Richmond until March 1865. Appomattox Campaign March 28-April 9. On line of Hatcher's and Gravelly Runs March 29âÂÂ30. Assault on Fort Gregg and fall of Petersburg April 2. Pursuit of Lee April 3âÂÂ9. Rice's Station April 6. Appomattox Court House April 9. Surrender of Lee and his army. Duty in the Department of Virginia until August.
The regiment lost a total of 367 men during service; 12 officers and 182 enlisted men killed or mortally wounded, 1 officer and 202 enlisted men died of disease.