Fort Clay was one of two forts built by the Union Army in Lexington during the Civil War. The fortification was constructed in 1863 on the southern ridge of the Davis Bottom valley to guard Versailles Pike, a strategic road leading into the western end of downtown Lexington. Fort Clay was built in response to a raid by Confederate General John Hunt Morgan on Union troops camped at Ashland, the estate of Henry Clay. The fort was planned and constructed by Captain T.B. Brooks, New York Volunteer Engineers, under the direction of Brigadier General Q.A. Gillmore. The official U.S. Engineers survey map (right) shows it was a starshaped structure with earthen and wood embankments and a surrounding ditch.