Cumberland Gap, natural passage through the Cumberland Mts., near the point where Virginia, Kentucky, and Tennessee meet. The gap was formed by the erosive action of a stream that once flowed there. It was explored and named in 1750 by Dr. Thomas Walker, leader of a land company exploration party. Daniel Boone's Wilderness Road ran through the gap. A strategic point in the Civil War, the gap was held alternately by Confederate and Union forces. Cumberland Gap National Historical Park was established in 1940 (see National Parks and Monuments, table).