Early in its training, it was so poorly equipped that a civilian who visited the troops wrote a letter to the editor of The New York Times (published May 16, 1861) complaining that tailors within the regiment had to resew the uniforms and put buttons on them, and that some of the soldiers were wearing "flip-flaps".

The business-like air with which they marched rapidly through the deep mud of the Third-avenue was the more remarkable.With "one or two exceptions" almost every officer then in the regiment had experience in European armies, and six out of eight of the soldiers had seen service, often in battle.

It took part in the engagement at Big Bethel and returned to camp at Newport News until in March, 1862, when it was assigned to the 1st Brigade, 1st Division, Army of Virginia.

On May 6, 1863, Colonel Von Schack received authority to reorganize, for a period of three years, the 7th New York, then about to be mustered out by reason of the expiration of its term of service.

[12] In spring, 1864, Col. George W. Von Schack, under his former authority, again commenced the formation of a regiment, under the above title, and the organization took place at Hart's island.

The regiment served in the Siege of Petersburg and Appomattox campaign in the Consolidated Brigade, 1st Division, II Corps, Army of the Potomac.

[25] By the end of the first full year of hard campaigning, the regimented returned 720 Model 1842 smoothbore percussion muskets to the Adjutant General.