The 1st Maine was originally formed in state service in 1854, and thus was older than any other Maine regimental organization. An historian of the 240th AAA (Anti-Aircraft Artillery) Group, a former Maine Army National Guard unit, has concluded that numerous subsequent Volunteer Maine Militia and Maine National Guard units, including the 10th Maine, inherited the lineage of the 1st Maine via the Portland Light Infantry company. In the 10th Maine, this lineage was carried by Company C, which included elements of the disbanded Cos. A and D of the 1st Maine. From 1924 through 1944 this lineage was carried by the 240th Coast Artillery Regiment. As of 2018 this lineage is carried by the 240th Regional Training Institute, Maine Army National Guard, in Bangor.