Prior to his service in Congress, he was a general in the Union Army during the American Civil War.

He then signed up for military service during the Mexican–American War, serving as a lieutenant colonel of the 4th Indiana Infantry Regiment.

Dumont was promoted to brigadier general of volunteers on September 3, 1861, and served until February 28, 1863, when he resigned from the army to resume his political career.

He was appointed by President Ulysses S. Grant as the Governor of Idaho Territory, but died in Indianapolis, Indiana, on April 16, 1871, before taking the oath of office.

This article incorporates public domain material from the Biographical Directory of the United States Congress