With the assistance of Senator James Harlan, the War Department authorized a military training camp at Mount Pleasant in October of 1861. The first recruits began arriving that September at Camp Harlan, which was designated as a cavalry training post for the Fourth Iowa Volunteer Cavalry. Twelve companies had been mustered by November 23, 1861 with 1086 men and officers. These first recruits found only an open meadow and piles of lumber to be used for barracks construction, with the people of the county providing food and blankets. The first companies left by train on February 25 when the Fourth Iowa received orders to move to Benton Barracks, St. Louis, Missouri.
Starting in August, 1862 a second regiment was organized, the 25th Iowa Volunteer Infantry, with the military post now called Camp McKean. Ten companies were mustered on September 27, 1862 with a strength of 972 men. After training under the command of Colonel George A. Stone, the first units left for St. Louis early in November.
Nine soldiers died while on duty at Camp Harlan and Camp McKean. They are buried in Forest Home Cemetery.