[1] It suffered more casualties in an ill-fated charge during the Second Battle of Petersburg than any Union regiment lost in a single day of combat throughout the war.

Charles Hamlin, son of Vice President Hannibal Hamlin, was originally an officer in this regiment, but was promoted to a position on the staff of Maj. Gen. Hiram G. Berry before it saw significant action.

At the Second Battle of Petersburg, however, an ill-advised charge across an open field toward Confederate breastworks on June 18, 1864, ordered by Chaplin, resulted in the greatest single loss of life in a Union regiment to occur in the war, with 7 officers and 108 men killed, and another 25 officers and 464 men wounded.

[5] The regiment was commanded by Russell Benjamin Shepherd for the remainder of the war.

All in all, the 1st Maine sustained one of the highest casualty rates in the war, with 423 killed, and another 260 died of disease.