[9] The regiment was formed on April 12, 1861, by a group of military enthusiasts in Manhattan, under authority issued to Colonel Abram Duryée, and trained at Fort Schuyler at Throgs Neck, New York Harbor.

[6] The regiment was mustered into Federal service of the United States at Fort Schuyler for a term of two years by Capt.

[12] The line officers were elected as well and resulted in the following:[13] On May 24, the regiment boarded a transport to reach the Virginia Peninsula.

The 5th's duty in Baltimore was marked by occasional clashes with pro-secessionist locals, patrolling the rail lines and yards, and improving the fort on Federal Hill.

The force landed above the state line on Wednesday, November 13, a proclamation calling on the militia to lay down their arms, promising protection for Unionists, and punishment for continued disloyal activities.

[27] To maintain discipline, punishments in garrison were harsh and in February, six members of the regiment who were chronic violators of army regulations were paraded to the "Rogue's March," and sent off in chains to the Washington Penitentiary and the military prison in the Dry Tortugas.

[28] In preparation for his upcoming offensive in the Peninsula campaign to capture Richmond, Virginia, General George McClellan ordered the regiment to join the Army of the Potomac.

As McClellan moved his base to the James River on June 27, 1862, the regiment fought against Gregg's South Carolina brigade.

Of the famous Texas Brigade's who elite soldiers accurate musket volleys quickly inflicted massive casualties in the regiment.

[32][33] The 5th New York were issued the Model 1842 Springfield Muskets .69 caliber, smoothbore when accepted by the state on Monday, April 29, 1861.

[34][note 10] At Fortress Monroe, companies E and K exchanged, with the Commissary General, their muskets for Sharps Model 1859 breech-loading rifles (.52 caliber).

[36][6] At some time prior to the Fredericksburg campaign, the regiment exchanged their 1842 Springfield smoothbores for a mix of model 1855, 1861 National Armory (NA) and contract[note 11] rifle-muskets, a handful of Enfield Rifled Muskets,[39][note 12] (.577 caliber, rifled) from stocks already in the State of New York's possession.

Photographic evidence suggests that later in the war the 165th was given replacement sashes that were a solid red color without the light blue trim.

After a long and difficult recruiting period, the 5th Veterans joined the V Corps and fought in the final campaigns of the Virginia front.

[46] In the fall of 1862, officers of the 5th detailed on recruiting duty had organized the 165th New York Volunteer Infantry, or "Second Battalion Duryee's Zouaves."

The 165th served with the XIX Corps in Louisiana, in Virginia's Shenandoah Valley, and on occupation duty in Charleston, South Carolina, at war's end.

[47] The 3rd Annual Report of the Bureau of Military Statistics stated "...no other New York regiment gave so many officers to other commands.