The Third Regiment was raised and sent to the front about August 1, 1861. Its First engagement was at Blue Mills, Mo., September 18, 1861. Fought gallantly at Shiloh two days, the second day under command of Lieut. Onsley, the regimental officers being off duty or wounded. At Metamora, October 5, 1862, the regiment suffered heavily. On its way to join Gen. Grant, before Vicksburg. July 12,, 1863, it went into battle at Johnson, Miss., with 241 men, and lost 114 killed, wounded and missing.  Participated in the Meridian expedition, arriving there February 3, 1864, and next day tore up fifteen miles of railroad. Near Atlanta, did good service, July 28. Greatly reduced in numbers, the survivors re-enlisted, forming three companies, and consolidating with the Second Infantry.