On the 25th day of April, 1861, the Regiment was organized at Springfield, and mustered in for three months' service. Richard J. Oglesby, of Decatur, was appointed Colonel. The regiment was immediately sent to Cairo. Companies A and D, in command of Capt. Isaac Pugh, were sent to Big Muddy river, to guard the railroad bridge, as there was danger of its destruction by rebel sympathizers, to prevent the transportation of troops and supplies. Relieved by other troops, these companies rejoined the regiment at Cairo. The regiment remained at Cairo during its term of service, when it was mustered out.

July 25th, 1861, the regiment reorganized and was mustered in for three years' service. It remained at Cairo until October, 1861, when it was ordered at Bird's Point, Mo. During this time it received a thorough drill, and attained a high state of discipline. With other troops it made expeditions to Cape Girardeau, Commerce, Bloomfield, and Norfolk, Mo., and Paducah and Blandville, Ky., and joined in the feint on Columbus, Ky., in January.

The move to Bloomfield is fixed in the memory of the soldiers of the Eighth by the raid on the rebel Colonel Hunter's well stocked farm, and the rapid return march from Bloomfield to Cape Girardeau. In November, the regiment constructed at Bird's Point extensive and comfortable quarters for the winter.

February 2d, 1862, it was taken up the Tennessee river to a point near Fort Henry. On the 5th it reconnoitered the enemy's position, approaching near enough to attack and drive in his outpost. It was among the first to enter the Fort, after its reduction by the gunboats.

February 11th the movement on Fort Donelson began. The next day, under command of Lieut. Col. Frank L. Rhoads (Colonel Oglesby commanding the Brigade), it was in the advance of the column, where it met a strong outpost of the enemy about noon, and after a few volleys dislodged and drove them toward their entrenchment. The regiment was moved towards the Cumberland river, on a ridge overlooking, in places, the enemy's defenses. On the 13th moved further to the right, gaining a position still nearer the enemy. During this night the weather became extremely cold, and the men suffered greatly--being so near the rebel picket line no fires could be had. A driving snow-storm set in, adding to the discomforts of the situation. Many were severely frost-bitten. On the 14th the regiment was in position near the Dover road, with pickets thrown well to the front, and in constant action with those of the enemy. Another night of intense cold, with sleet and snow was experienced, and at early dawn on the 15th the enemy came out in massed columns and attacked us. Out men were quickly in line, and although stiffened and suffering with the cold, they met the first onset and stood their ground for about three hours, when, ammunition exhausted and the brigade to the right giving away, if was forced to retire. The regiment lost in this battle 57 killed, 191 wounded, and 10 missing. Major John P. Post was captured. Among the killed were Capt. Joseph M. Hanna and Lieut. Daniel A. Sheetz, F. Co., and Lieut. Henry Y. Marsh, B. Co., and Lieut. Joseph G. Howell, K Co., acting adjutant.

On the 6th of March the regiment embarked for Savannah on the Tennessee river, and a few days after for Pittsburg Landing. Here it was in McClernand's Division, and brigaded with the 18th Illinois, the 11th and 13th Iowa Regiments. The camping ground was excellent for drill, and the time was well occupied with that and other camp duties.

Sunday morning, April 6, when called into line for the impending battle of Shiloh, there were 25 officers and 453 enlisted men. The regiment was in command of Captain James M. Ashmore, C Co.; Lieutenant-Colonel Rhoads being absent sick, and Major Post a prisoner of war. The regiment was moved rapidly to a position of left of Sherman's Division, and not far from Shiloh Church. At once it received a fierce attack from the enemy, but held its ground. Captain Ashmore was wounded and left the field. Captain William M. Harvey, K Co., nest in rank, took command and nobly lead the regiment until about 10 o'clock A.M., when he received a shot through his body and died instantly. The fight at this time was furious and the regiment was forced back, but recovering and reforming, it drove the enemy back over the ground it had lost. Captain Robert H. Sturges, H Co., next in rank, took command, and led the regiment with steady courage throughout the great battle. At night the regiment lay on the field exposed to the storm of rain that fell, and ready for the conflict of the succeeding day. It was in the front lines that early moved against the enemy on Monday morning, and performed it share in the battle of the day. Near the close of the second day's fight, the regiment, with the 18th Illinois, under the immediate orders of General McClernand, charged upon and captured a rebel battery, which was pouring a destructive fire upon our lines; some of the gunners were killed at their posts. The regiment lost at Shiloh 26 killed, 95 wounded and 11 missing. Among those wounded were Captain Loyd Wheaton, E Co,; Lieutenant Geo. S. Durfee, A Co., and Adjutant Monroe.

When the movement against Corinth began the regiment was in a brigade under the command of General John A. Logan, and in McClernand's reserve division. It experienced the fatigues of the approach, followed closely by the advanced troops, and often thrown far out to cover the right of the advancing lines.

After the evacuation of Corinth, the regiment marched to Bethel, Tenn., and thence to Jackson. Here it was brigaded with the 7th Mo., 63d and 81st Ill., Colonel John D. Stevenson, of the 7th Mo., commanding the brigade, in General Logan's Third Division. During the summer it took part in various movements to neighboring points, and as often as possible pursued its company and battalion drills. The movement to Bolivar by railroad, and the march thence to Brownsville, was a picnic, and the boys will remember the old white horse which was so generously offered to Colonel Rhoads by the colonel commanding the column.

Returning to Jackson, the regiment was sent down the railroad to Toones and Medon stations. The two companies at Medon were under command of Captain Herman Lieb, B Co., and under his direction put the depot building in splendid condition against attack.

October 2, 1862, the regiment formed a part of a column of troops hastily organized and marched rapidly to the relief of the army at Corinth. General Oglesby, the first colonel of the Eighth, was severely wounded in the battle of Corinth, being in command of his brigade at the time.

November 10, 1862, the regiment was ordered to LaGrange, Tenn., and was in General Logan's Division in the 17th Army Corps, under General McPherson. It took part in General Grant's movement down the line of the Miss. Central R.R. The regiment marched as far south at Oxford, Miss. Very little fighting ocurred, as the enemy fell back as Grant's army advanced. The cutting of the line of communication between Columbus and Jackson, and the capture of Holly Springs and destruction of supplies there collected, caused Grant to fall back to the Tallahatchie river, and finally to Memphis. The regiment camped at Tallahatchie about ten days, subsisting upon such supplies as could be foraged from the country--corn and molassas being the chief reliance.

January 4, 1863, the regiment broke camp and marched to Grand Junction, Tenn., arriving on the 9th. There was almost continual rain and the roads were in terrible condition. On the 12th started for Memphis/ Reached Lafayette in the midst of a heavy rain storm and went into camp. The weather turned very cold and everything was frozen for a day or two, occasioning much suffering.

Here Col. John P. Post joined the regiment, having been a prisoner, part of the time in Libby, since the battle of Donelson.

January 19th, the regiment marched to Memphis and camped on the Hernando Road just out the city limits.

February 22, 1863, embarked on steamer for Lake Providence, La. Soon after in concequence of high water, the regiment moved camp to Berry's Landing. It performed its share of the ardous work of cutting a channel throuh Byou Baxter. It went on foraging expeditions to points on the Mississippi river. When Gen. Grant determined to run past the rebel batteries at Vicksburg, the transports selected for the purpose were all but one abanconed by their crews, and volunteers were called from the army to man them. Lieuts. William P Sitton, G Co., and Thomas J. McClung, K Co., and 12 men of the Eighth were among those selected out of the hundreds that promptly offered their services for the dangerous undertaking. They were in the "Moderator," and passed through the storm of shot and shell with but few casualties.

April 12th the regiment went to Milliken's Bend, the rendezvous of most of the troops which were to make the memorial movement down the river, cross it and attack Vicksburg from the rear.

On the 25th it marched out through Richmond and to Perkins' Landing, and thence to DeShroon's Landing, and crossed the river to Bruinsburg, and took part in the stubborn battle of Port Gibson and the fight at Thompson Hill, in which Captain Elihu Jones, G Co., was severely wounded. With its brigade the regiment forded Bayou Pierre, waist deep in water, and pushed on through Willow Springs and Rocky Springs to Utica. At Raymond the enemy made a determined stand. They were strongly posted on a hill to the left of the road and in the deep ravine in front. About 11 o'clock A.M. of May 12th, Logan's Division attacked them, and a furious battle ensured. The Eighth was moved up the road, the wagon train being turned aside, and was soon in line of battle, and won great distinction by charging the enemy and relieving the center, which was hard pressed. In this engagement it lost one of its bravest officers, Captain Frank Leeper, A Co., killed . The other losses were 5 killed and 15 wounded. May 14th it took part in the capture of Jackson, and on the 16th the bloody battle of Champion Hill. In this battle the brigade in which was the Eighth, commanded by Col. John D. Stevenson, was moved to the extreme right of the line, and, under the immediate orders of Gen'l Logan, it charged up the hill on its northern slope and captured a battery of six guns, horses, caissons and all.

On the night of the 17th, aided in constructing a bridge near Big Black River, and on the next day crossed and pushed on to Vicksburg. On the 19th gained a position very near Fort Hill, on the main Jackson road. On the follwoing day took part in the general assault which had been ordered by General Grant at 10 o'clock A.M. The regiment did its share of the work incident to the approach on Fort Hill, and was in the trenches on June 25, when the mine was fired under the fort ready to push through the opening it was expected to make and enter the rebel lines. The interview between Grant and Pemberton was just in front of the regiment's position. After the surrender on the 4th of July, the regiment being in Logan's Division, which had approached nearest to the enemy's works, was among the first of the troops to enter the town. July 4 the regiment was posted on the Jackson road at Fort Hill, and acted as guard as the paroled rebel troops passed out.

August 21, 1863, the regiment, under Lieutenant Colonel Josiah A. Sheetz, formed a part of the expedition to Monroe, La., returning September 2.

October 12, moved with the 17th Army Corps, under General McPherson, towards Canton, Miss. Near Brownsville, in an engagement, lost two men wounded.

On the 18th, returned to camp at Vicksburg. Picket guard and patrol duty and drill occupied the time until February 3, 1864, when it moved, with the army under General Sherman, to Meridian, Miss. On the march had several encounters with small bands of the enemy, and did its share of foraging on the country.

March 24, 1864, the regiment re-enlisted as a veteran organization, and was sent on furlough to Camp Butler, Ill. Teturning to Vicksburg, the veterans of the 17th Ill. Regiment were consolidated with it, adding to its strength and efficiency.

July 1, formed part of the expedition to Jackson, Miss., under command of General Elias S. Dennis. Occupied Jackson on the 5th. Returning towards Vicksburg on the 6th towards night, found the enemy in considerable force in position to dispute the march, and skirmished until dark. At daylight the following morning, charged upon the rebels and drove them from their position, opening the road and permitting the safe passage of the wagon train. In this spirited action the casualties were 3 killed, 21 wounded, and 2 missing.

From 29th July to September 3, engaged in the Morganzia expedition. Embarked for mouth of White river, arriving on the 8th. Remained in camp here until October 18, when the regiment embarked for Memphis, Tenn. Camped at Fort Pickering until the 29th, and was ordered again to White river.

November 9, proceeded to Du Vall's Bluff, and remained there till the 28th, when it was again ordered to Memphis.

On the 29th of December, marched to Moscow, returning to Memphis on the 21st.

January 1, 1865, left Memphis for New Orleans, arriving on the 4th, and camped in the mud at Kennersville.

February 4, moved to Lakeport, and embarked on Lake Pontchartrain to Dauphin Island at Mobil Bay, being part of the army under General E.R.S. Canby, organized for the campaign against Mobile.

While here the regiment received a large number of recruits, making its ranks full. These new men assigned to the different companies soon learned from the veterans the duties of the soldier, and made the regiment one of the largest and most effective in the service. March 17th the regiment crossed the bay to Navy Cove, and moved with the army on Mobile. On the 26th reached the vicinity of Spanish Fort and entrenched. For four days worked in the approaches to the fort, having frequent engagements with the enemy, and a number of our men were killed and wounded. On the 30th was ordered towards Blakely, Ala. The following day camped within four miles of the regimen and worked in the trenches and extended saps until on the 9th it occupied a position close up to the rebel works. At 5 o'clock P.M. of the 9th the regiment took part in the grand assault on the fort, doing gallant service and planting its colors first on the earthworks. The loss in this charge was Simonson, E Co. On the 12th of April the regiment was sent across the bay, and marching on the shell road was the first to enter the city of Mobile. Here it remained, performing patrol and guard duty and undergoing a thorough company and battalion drill, until May 27th, when it embarked again for Lakeport.

On the 29th camped on the race course just out the city of New Orleans. May 31st left the city and proceeded up the Mississippi and Red rivers to Shreveport, La., arriving on the 9th. On the 16th was ordered to Marshall, Texas, where it remained in camp, engaged in guard duty and occasional expeditions for the protection of government property and officials, until late in fall of 1865, when it was ordered to Alexandria, La. Here it remained until the spring of 1866.

The regiment was finally ordered to Baton Rouge, Miss., where on May 4, 1866, it was mustered out and sent to Springfield, Ill. Arriving at Springfield May 13th, it received its final pay and was honorably discharged, after a service of five years' duration.