Putnam County was deeply divided during the Civil War, with local residents enlisting in both Federal and Confederate units, and its roads made it a crossroads repeatedly used by both armies. Although no major engagement by regular armies occurred there, forage raids, conscript sweeps, bushwhacking, and small skirmishes were common. During a reconnaissance expedition near Cookeville, Union Col. Henry K. McConnell's troops killed 23 Confederate partisans and captured another 40. The Battle of Dug Hill on February 24, 1863, became the county's best-known fight when Confederate Col. John M. Hughs's rangers ambushed a detachment of Col. William B. Stokes's 5th Tennessee Cavalry along the Calfkiller River and killed more than 40 men. Much of the suffering endured by citizens came from continuing guerrilla activity in Putnam and nearby counties, bringing destruction of lives and property and leaving wounds and animosities that took decades to heal. The Johnson and Calfkiller caves near Monterey supplied saltpeter for gunpowder, the 4th Confederate Cavalry mustered in the Calfkiller Valley, White County's Confederate Gen. George G. Dibrell of the 8th Tennessee Cavalry at one time used Dry Valley as his headquarters, and Union Gen. John T. Wilder of the "Lightning Brigade" made Monterey his home after the war.