The 91st New York Infantry Regiment lost 3 officers and 110 enlisted men killed or mortally wounded and 1 officer and 184 enlisted men to disease during the Civil War.
|September – December||Organized at Albany, N.Y. under Colonel Jacob Van Zandt, Lieutenant Colonel Jonathan Tarbell and Major Charles G. Clark|
|January 9||Left State for Washington, D.C. then moved to Pensacola, Fla.|
|January||Duty at Key West, Fort Pickens and Pensacola, Fla. attached to Brannan’s Command, District of Florida|
|March||Assigned to District of Key West, Fla., Dept. of the South|
|August||Asigned to District of West Florida, Dept. of the Gulf|
|August 7-10||Expedition from Pensacola to Bagdad and Milton, Fla. (Companies I and K)|
|August 23||After a bitter dispute with Colonel Van Zandt, Lieutenant Colonel Tarbell was court martialled for disobedience and dismissed from the service.|
|October 27||Action at Gonzales, Fla.|
|December 17||Ordered to New Orleans, La. then to Baton Rouge, La., and occupation of that city. Assigned to Grover’s Division, Dept. of the Gulf.|
|January||Assigned to 1st Brigade, 3rd Division, 19th Army Corps, Dept. of the Gulf, then to 2nd Brigade, 4th Division, 19th Army Corps|
|March 7-27||Operations against Port Hudson assigned to 1st Brigade, 4th Division, 19th Army Corps.|
|March 26||Moved to Donaldsonville then to Brashear City.|
|April 9-May 14||Operations in Western Louisiana|
|April 11-20||Teche Campaign|
|April 13||Madam Porter’s and McWilliams’ Plantations at Indian Bend|
The regiment lost 2 men wounded, 1 mortally,
|April 17||Vermillion Bayou|
|May 24-July 9||
Siege of Port Hudson
The regiment assaulted the Confederate lines with five pound hand grenades. It lost 3 officers and 44 enlisted men killed or mortally wounded, 7 officers and 91 men wounded, and 4 men missing.Colonel Van Zandt comanded the brigade as senior colonel. Major Stackhouse, commanded the regiment and was mortally wounded in both legs. Captain Henry Hurlburt and Lieutenant S. A. Shepherd were killed, and Captains Cooke and Lee and Lieutenants Heremeth, Matthias and Diamond wounded.
and June 14
Assaults on Port Hudson
|June 1863||After extensive legal manuevering and a petition in his favor signed by almost all of the regiment, Lieutenant Colonel Tarbell returned to duty with the regiment.|
|July 9||Surrender of Port Hudson|
|July 12-13||Kock’s Plantation, Donaldsonville, Bayou LaFourche|
|July||Garrison Duty at Fort Jackson, Defenses of New Orleans, Dept. of the Gulf equipped as heavy artillery.|
|August||On Veteran furlough. Colonel Van Zandt left the regiment and was court martialled.|
|October||Duty in defenses of Baltimore, Md., 8th Army Corps, Middle Department. Company E detached at Baltimore, Md. until muster out.|
|February||Ordered to join Army of the Potomac before Petersburg, Va. and assigned to 1st Brigade, 3rd Division, 5th Army Corps, Army of the Potomac.
Colonel Van Zandt was dismissed from the service as a result of his court martial. Lieutenant Colonel Tarbell was promoted to colonel, Major William Denslow promoted to lieutenant colonel, and 1st Lieutenant Albert Wagstaff promoted to major.
|March 1-April 2|
|March 28-April 9||
The regiment lost 62 enlisted men killed or mortally wounded, 6 officers and 146 men wounded, and 17 men missing in the campaign.
|March 29||Lewis Farm, near Gravelly Run|
|March 30-31||Boydton and White Oak Roads|
|April 3-9||Pursuit of Lee|
Surrender of Lee and his army.
|May 1-12||March to Washington, D.C.|
|May 23||Grand Review|
|June||Duty at Washington assigned to 3rd Brigade, 3rd Division, 5th Army Corps|
|July 3, 1865||Mustered out under Colonel Tarbell, Lieutenant Colonel Denslow and Major Wagstaff.|