The Forty-eighth Infantry Illinois Volunteers was organized at Camp Butler, Illinois, in the month of September 1861, by Colonel Isham N Haynie. The Regiment left Camp Butler, for Cairo, November 11, 1861, nine hundred strong, and, after its arrival, constructed barracks for winter quarters. In January 1862, was engaged in the reconnaissance in the rear of Columbus, under General Grant. February 2, embarked for Fort Henry, in W.H.L. Wallace's Brigade, General McClernand's Division. Landed a few miles below the fort, and was the first Federal regiment that formed a line of battle in Tennessee. February 6th, entered Fort Henry, which had surrendered to the gun-boats. February 11, moved toward Fort Donelson. 13th, in connection with the Seventeenth and Forty-ninth Illinois, Colonel Haynie commanding Brigade, charged the enemy's works, but was repulsed with a severe loss. 14th, was under fire during the day, losing men wounded.

February 15, was in position by the side of the Eleventh and Twentieth. The rattle of musketry, on the right, was incessant, and gradually approached the left, where the Forty-eighth was stationed, on the brow of the hill, and it was soon fiercely engaged. The enemy were twice repulsed from the front of the Forty-eighth, but they finally succeeded in turning the right of our line, and the Regiment was compelled to retire and form a new line, where the enemy was again repulsed, and he retired within the works. The Regiment lost, this day, forty killed and wounded. Among the killed was the gallant, daring and courteous Lieutenant Colonel Thomas H. Smith. The Regiment moved, with General McClernand's Division, to Savannah and to Pittsburg Landing. April 6 and 7, was engaged in the battle of Shiloh, the Regiment bearing its full part, and losing over half of its men, killed and wounded. Colonel Haynie and Lieutenant Colonel Sanford were both wounded on the 6th.

Was engaged in the siege of Corinth, May 1862, and in June ordered to Bethel, as garrison of that post. Remained there until 1863.

Colonel Haynie was promoted to Brigadier General November 29, 1862

March 9, 1863, the Forty-eighth was assigned to William S. Smith's Division, of the Sixteenth Army Corps. Colonel Sanford taking command of the Brigade, Lieutenant Colonel Greathouse assumed command of the Regiment. It moved from Germantown to Memphis, June 9, and from thence to Vicksburg, where it participated in the operations in the read of that place, and at Snyder's Bluff. Advanced with General Sherman's force, against Jackson, arriving at that place, July 11, 1863. It participated in the siege and in the charge of the 16th inst., losing 45 men killed and wounded. Among the killed was Major William J. Stephenson.

The Regiment left Black River, on its return north, September 30, arriving at Memphis, October 10, and leaving for Chattanooga, 11th, a march of over 400 miles.

After arriving at Chattanooga, was engaged in operations in Lookout Valley. Took part in the battle of Mission Ridge, following the retreating enemy to Ringgold. From here it was ordered to Knoxville, Tennessee, to the relief of General Burnside. Without rations, blankets or overcoats, and but half shod, the made a march of two hundred and seventy miles. The men used their blankets, jackets and trousers to protect their feet from the sharp rocks, the ice and the snow. Returned to Bridgeport, Alabama, December 17. Arrived at Scottsboro, Alabama, January 1, 1864, and although not yet recovered from their severe campaign, over none-tenths of the men present re-enlisted as veteran volunteers.

Arrived at Springfield, Illinois on veteran furlough, January 27, 1864, where the Regiment was furloughed; rendezvoused at Centralia.

Moved from Centralia, Illinois, March 10m 1864m via Louisville, Kentucky, Nashville, Tennessee, and Scottsboro, Alabama, and returned to Chattanooga. May 3, 1864 from thence via Resaca, Dallas, Kenesaw Mountain, to Atlanta. In the Hood campaign, moved to Marietta, Resaca and to Jacksonville, Alabama, and returned to Atlanta.

November 15, 1864, moved with General Sherman's Army, arriving at the fortifications of Savannah, December 11, and at Fort McAllister, 13th. Thence to Savannah, January 1, 1865. From thence, by water to Beaufort. Thence moved, January 21, via Pocotaligo, to Goldsboro, N.C. From thence April 10, to Raleigh. Thence via Lewisburg, Warrenton, Lawrenceville, Petersburg, and Richmond to Washington D.C. From thence June 2, 1865, via Parkersburg, Virginia to Louisville, Kentucky.

June 25, moved to Little Rock, Arkansas. Mustered out august 15, 1865, and moved to Camp Butler, Illinois, arriving August 21, 1865.

Distance marched, 3,000 miles. Moved by water, 5,000 miles; by railroad, 3,450. Total 11,450.