In November 1861 some 10,000 Union troops, mostly from Kentucky, Indiana, and Ohio, were sent to Calhoun to protect Lock and Dam Number 2 and the Green River commanded by Maj. Gen. Thomas L. Crittenden, the troops remained in the area until February 1862 when they were moved south as the Union army undertook initiatives that would ultimately lead to the Vicksburg campaign. While at Calhoun the troops established Camp Calhoun, located west of present-day downtown Calhoun.

This site has local significance because it is associated with military events and activites that achieved or affected important local objectives of the Vicksburg campaign.