Duvall served in the US Navy until he was discharged in 1860 due to an incurable disease. He was appointed lieutenant in the North Carolina Navy by the Military and Naval Board after secession in 1861. He commanded the Beaufort, the second gunboat commissioned by the state navy, until 20 August 1861. The NC Navy had been sold to the Confederate government in July of 1861, but the state retained control of the Winslow and Beaufort until 20 August 1861 in the deal. Duvall left the ship in New Bern on the 20th and traveled to the Warrenton area, where he received a letter from the Board concerning paying off the Beaufort crew. Duvall died in Raleigh 4 Feb. 1863. He was rejected for service in the CS Navy in 1861 due to his incurable disease.
Duvall ended up in Yadkin County in the 1860 census after being discharged from the US Navy because of his mother. His father had died and she had remarried to a man named Cowles. Cowles lived in Hamptonville, located in Yadkin County. Duvall lived with them after his discharge. After Duvall died in Raleigh, his body was shipped to the town where his mother was living for burial. Duvall was buried in Flat Rock Baptist Cemetery in Hamptonville.
Duvall was half-brother to Henry Clay Cowles of Statesville, deputy clerk of court for the Circuit and District Courts. Cowles was born in Hamptonville around 1845. He had possession of Duvall’s logbook from the Beaufort after the war and loaned it to the government agency creating the Official Records of the Navy in the late 1800s and early 1900s. The logbook ended up in the National Archives, so it obviously wasn’t returned to Cowles in Statesville, NC, as the note on the cover requested.