James H. Coburn was born in December of 1836 in Connecticut. Before the war he was a merchant in New Haven.

At the start of the war he joined the 2nd Connecticut Infantry Regiment, a three months regiment, as a private.

On October 3, 1862 he became captain of Company A of the 27th Connecticut Infantry. He had risen to the rank of major by July of 1863, and took command of the regiment at Gettysburg when Colonel Henry Merwin was killed on July 2nd. Coburn mustered out on July 27, 1863.

He died on Dec. 20, 1899 in Bromley, Iowa.