He was a direct descendant of Vincent Rongion (1644–1713), a Huguenot who was born in Poitiers, France and settled in New Jersey.

[1] Theodore Runyon graduated from Yale University, where he helped found Scroll and Key Society.

As a brigadier general in the New Jersey militia, Runyon commanded the Fourth Division of the Army of Northeastern Virginia in June and July 1861.

Fort Runyon, named in Theodore Runyon's honor, was a timber and earthwork fort constructed by the Union Army following the occupation of northern Virginia in order to defend the southern approaches to the Long Bridge as part of the defenses of Washington, D.C. during that war.

Runyon was appointed major general in charge of the New Jersey National Guard, and served in this post until 1873.