"Cumberland Gap." YourDictionary, n.d. Web. 21 September 2018. <http://www.yourdictionary.com/cumberland-gap>.
Cumberland Gap. (n.d.). Retrieved September 21st, 2018, from http://www.yourdictionary.com/cumberland-gap
A natural passage through the Cumberland Mts. near the junction of the Kentucky, Virginia, and Tennessee borders. It was used by Daniel Boone in 1775 as a strategic point along his Wilderness Road, the principal route of westward migration for the next half century.