During the Civil War, he served as first lieutenant and adjutant of the Forty-fourth Regiment, Indiana Volunteer Infantry; subsequently became a major in the Third Regiment, Indiana Volunteer Cavalry, and served from November 26, 1861, - August 15, 1862.
He later resumed the practice of his profession in Washington, D.C.
Peggy Seigel, "Charles Case: A Radical Republican in the Irrepressible Conflict," Indiana Magazine of History, vol. 107, no. 4 (Dec. 2011), pp. 327–360. In JSTOR