The 2nd Maine Volunteer Infantry Regiment was called into service the same time as the 1st, and saw action during the Seven Days Battles, 2nd Bull Run, Antietam, Fredericksburg, and Chancellorsville. The regiment's enlistments ran up in 1863, but about half the unit had signed papers to serve for the three years, so they were amalgamated into the 20th Maine Volunteer Infantry Regiment.