The 186th New York Infantry lost 48 enlisted men killed or mortally wounded and 1 officer and 39 enlisted men to disease during the Civil War.

1864
Organized at Sackett’s Harbor, N.Y. under Colonel Bradley Winslow
September 5 Companies A and B mustered in
September 7 Companies C and D mustered in
September 8 Companies E and F mustered in
September 10 Company H mustered in
September 17 – 21 Bradley Winslow mustered in as colonel, E. Jay Marsh as lieutenant colonel and Abram Sternberg as major
September 21 Company I mustered in
September 26 Company G mustered in at Hart’s Island, N.Y
September 28 Left State for Petersburg, Va.
September 29 Company K mustered in
October 1 Siege of Petersburg, Va. Attached to 2nd Brigade, 2nd Division, 9th Army Corps, Army of the Potomac
October 27-28 Boydton Plank Road, Hatcher’s Run
March 25 Fort Stedman, Petersburg
1865
March 28-April 9 Appomattox Campaign
April 2
Assault on and fall of Petersburg.

The regiment suffered severe casualties attacking Fort Mahone, losing 48 enlisted men killed or mortally wounded, 11 offiicers and 115 men wounded and 6 enlisted men missing. Colonel Winslow was wounded leading a charge the Fort, and was eventually discharged for disability.

April 3 Occupation of Petersburg
April 20-27 Moved to Washington, D. C. and duty at Alexandria, Va.
May 23 Grand Review
June 2 Mustered out near Alexandria, Virginia under Lieutenant Colonel Marsh and Major Sternberg. Recruits transferred to 79th New York Infantry