Isaac Bledsoe was born in Culpepper County, Virginia, but as a young man settled with his brother Anthony on the Holston River a few miles west of Bristol. After serving with British colonial troops in Lord Dunmore's War, he hunted and explored extensively along the Cumberland River. In 1772 he discovered Bledsoe's Lick and Bledsoe's Creek in an area of North Carolina that later became Sumner County, Tennessee. He was a captain in Colonel William Christian's Cherokee expedition in 1776; the next year he commanded a company to protect the border settlements. During the autumn of 1779, Commissioners Thomas Walker and Daniel Smith chose him for the party to survey the Virginia-North Carolina state line. They selected him for his firsthand knowledge of the western country, but he went in order to select a site for the stockaded fort he had agreed to build near Bledsoe's Lick as part of the proposed Cumberland settlements. One of the court of triers of the original Cumberland Association, Bledsoe was a justice of the peace in the first Davidson County Quarterly Court in 1783, first major of the county militia, and a guard for the surveyors of the North Carolina Military Reservation. When Sumner County was created from eastern Davidson County in 1786, Bledsoe served in the first Sumner County Quarterly Court, was first major of the county militia, and became lieutenant colonel commandant in April 1788.
In 1772 Isaac Bledsoe married Katherine Montgomery, a sister of the veteran frontiersman Colonel John Montgomery. The Bledsoe family lived at Mansker's fort in 1782-83, but moved into Bledsoe's fort about 1784. They had eight children. Indians shot and killed Isaac Bledsoe while he was working in a field near his fort on April 9, 1793. Eleven months later, his son Anthony fell mortally wounded in an Indian attack near Daniel Smith's Rock Castle home.