Thomas Gaddis (1742–1834) was an officer in the American Revolutionary War. He was born December 28, 1742, in Winchester, Frederick County, Virginia and married Hannah Rice in 1764; the same year he built Fort Gaddis, a refuge from the Indians, located on the Catawba Trail. In fact, Pennsylvania and Virginia had conflicting claims in the area Gaddis settled. Though he maintained his loyalty to Virginia, Gaddis also protected his investment by recording his patent with Pennsylvania authorities. By 1773, both states created new geo-political boundaries in recognition of increased white settlement. Pennsylvania formed Westmoreland County out of the larger Bedford County, and Virginia established the District of West Augusta. In 1776, West Augusta was further divided into three counties: Ohio, Youghiogheny, and Monongahela, where Gaddis and his family resided.
Gaddis enlisted as a private in Captain Robert Bell’s company, in the 13th Virginia Regiment under Lieutenant Colonel John Gibson. He was then detached to serve under Captain Uriah Springer, assisting in the construction of Fort Liberty (Monongahela County), Fort McIntosh, and Fort Lawrence.
Thomas Gaddis was appointed captain of the militia in Monongahela on August 23, 1776. From September 1776 to January 1777, Gaddis was stationed near Beech Bottom, West Virginia, about ten miles north of Fort Henry (West Virginia). While stationed there, he was primarily responsible for keeping communications open to Fort Henry, and for scouting the countryside for hostile Indians. On February 17, 1777, he was commissioned as a lieutenant colonel, then to full colonel by Patrick Henry, Governor of Virginia. Subsequently, Gaddis took command of Fort Pickett, Fort Scott, Fort Stradler, Fort Jackson, and Fort Lindley.