[1] The 100th, known as the Round Head Regiment, was recruited in the southwestern part of the state in Aug. 1861, and ordered to Washington on Sep 2, where its organization was completed add it was mustered into the U. S. service for a three years, term.

After various marches during the month of August, the regiment met the enemy on the Bull Run battlefield, where it saw hard service.

It was engaged at Fredericksburg and after the battle performed important duty in covering the withdrawal of the troops, being selected as "The most reliable skirmish regiment in the brigade."

In March 1863, it was transferred to the Department of the Ohio and sent to Lexington, Ky., from which place it was ordered in June to the support of Gen. Grant at Vicksburg.

It participated in an engagement at Blue Springs and in the hardships of the Siege of Knoxville, in spite of which almost the entire regiment reenlisted on January 1, 1864.

At Annapolis, the rendezvous of the 9th Corps, the 100th reported in March and became a part of the 2nd Brigade, 1st Division, attached to the Army of the Potomac.