Thornburgh's father, a prominent Unionist, was arrested by Confederate authorities during the war and died in a Confederate prison in Georgia. His brother, Thomas, enlisted in the Sixth East Tennessee Volunteers and rose through the ranks, establishing a career as an officer in the military.
Thornburgh's father, who was a notable Unionist, was taken into custody by Confederate authorities during the war and later died in a Confederate prison in Georgia. His brother, Thomas, joined the Sixth East Tennessee Volunteers and rose through the ranks to become an officer in the military.