John Marshall Brown (1838-1907) of Portland enlisted in the Union Army in August 1862. Pictured here with the rank of captain, Brown first served as adjutant in the 20th Maine Regiment. In the summer of 1863, with the rank of captain, he was promoted to Assistant Adjutant General under fellow Maine solider Gen. Adelbert Ames in the 11th Corps.

With the rank of lieutenant colonel, Brown commanded the 32nd Maine Regiment at the Siege of Petersburg, where he was wounded in the chest and left arm on June 19, 1864. After a difficult recovery, Brown mustered out in September 1864.

After the war, he was first brevetted to the rank of colonel and eventually to brigadier general.