In April 1861, the 3rd New Jersey Volunteer Infantry was formed, which was an American Civil War Union Army infantry regiment that served in the Army of the Potomac.

It was recruited and mustered under the authority of General Orders No. 15, War Department, Adjutant General’s Office, Washington, D.C, May 4, 1861 and was brigaded with the 1st New Jersey Volunteer Infantry, the 2nd New Jersey Volunteer Infantry, and the 4th New Jersey Volunteer Infantry to make up the now famous First New Jersey Brigade.

On June 4th, the 3rd New Jersey Volunteer Infantry was duly mustered into service of the United States for 3 years at Fort Olden, Trenton, N.J. It left the state on June 28, 1861 with a full compliment of men, as follows: Officers- 38, Non-Commisioned Officers and Privates- 1013, totaling 1051.