The 18th New Hampshire Infantry Regiment lost 1 officer and 4 enlisted men killed or mortally wounded and 36 enlisted men to disease during the Civil War.

September 13 Organized at Concord. First six Companies recruited under call of July 19, 1864
September Six Companies ordered to City Point, Va. for duty in Fortifications at City Point, Va. attached to Benham’s Engineer Brigade
December 10-13 At front near Petersburg
December 18 Reported to Gen. Ferrero, and duty in the Defenses of Bermuda Hundred attached to Clough’s Provisional Brigade, Ferrero’s Division
December 21 Four Companies organized at Concord. Company K assigned to duty at Galloupe’s Island, Boston Harbor, entire term.
December 30 Duty at City Point
February Company G joins regiment
March Company H joins regiment
March 19 Reported to Gen. Parke, Commanding 9th Army Corps, before Petersburg and attached to 3rd Brigade, 1st Division, 9th Army Corps, Army of the Potomac,
March 25 Repulse of attack on Fort Stedman
March 25-April 2 Duty at Fort Stedman
March 28-April 9 Appomattox Campaign
April Company I joined the regiment
April 2 Assault on and fall of Petersburg
April 3 Occupation of Petersburg
April 4 Moved to South Side Railroad and duty at Ford’s Station
April 20-26 Moved to Washington, D.C.
April 26 Camp at Alexandria and Provost duty at Georgetown.
May 6 Company K mustered out on at Galloupe’s Island, Boston Harbor
May Guard duty in Washington during trial of President Lincoln’s assassins.
June 10 Six original companies muster out
July 29 Companies G, H & I muster out