Colonel Hogg was a popular anti-slavery speaker. His intimate familiarity with slavery, his love for and understanding of the Southern people and his appreciation of their entanglement with that blighting institution, enabled him to present his side of the case with great fairness, force and conviction. Governor Yates was so strongly impressed with his ability that, upon the organization of the Second Illinois Cavalry, he tendered him the position of Lieutenant Colonel. It was at once accepted, and on July 24th, 1861, he was mustered into the service.
While his regiment was stationed in Tennessee, Mrs. Hogg went there to be near him, but died soon after her arrival. This was a severe blow to her husband who was devotedly attached to her.
During the winter of 1861-2, the regiment was stationed at Paducah, Kentucky, where much scouting was done. On the night of March 2nd, 1862, Lieutenant Colonel Hogg with two hundred men, started out in an attempt to reconnoiter Columbus, Kentucky. Upon the following day they learned that the place was being evacuated. Reaching it about sundown, they dashed into the town with drawn sabers and ran up the stars and stripes. Several large guns and a considerable quantity of military stores were secured. Upon the following day, General Sherman, with a fleet of gunboats and transports and three regiments of infantry, steamed carefully down the river and was surprised to find the place in possession of the Union forces.
On March 31st, 1862, Colonel Hogg, with two companies of his regiment, took part in an expedition under General Quimby in the neighborhood of Union City, Tennessee, in which they dispersed a Confederate brigade, destroyed its camp-equipage and captured fourteen prisoners and a considerable quantity of stores.
On July 4th, 1862, at Trenton, Tennessee, Colonel Hogg delivered an address to the citizens of that place and vicinity which produced a marked effect upon those who were in doubt and did much to aid the Union cause.
This valiant soldier met his death at the battle of Bolivar, Tennessee, on August 30th, 1862. Colonel M. D. Leggett, of the 78th Ohio, being at that place, was attacked by a large force of Confederates, including the Second Missouri Cavalry, commanded by Colonel Robert McCullough and the First Mississippi Cavalry, of which Colonel Hogg's half brother, Dr. Grant A. Hogg, was surgeon. The following report of the battle is given by Colonel Leggett:
"The infantry reinforcements had not arrived. The balance of the Seventy-eighth Ohio was reported close by, but not near enough to support the artillery, hence it could not be used. At this point, Lieut. Col. Harvey Hogg, of the Second Illinois Cavalry, came up with orders from you to report to me upon the field with four companies of his command. I immediately assigned him a position upon the right of the road, but discovering that the enemy would probably make a cavalry charge upon us before Colonel Force could reach me from Van Buren Road, I asked Colonel Hogg if he could hold a position on the left of the road and a little to the front of where he then was, against a charge from the rebel cavalry. He promptly said he could and besought me to give him the position, which was done.
"He had not completed his change of place before the enemy charged down the line of the road in vast numbers, but meeting the deadly fire of the four infantry companies under command of Captain Chandler, they were compelled to retreat, leaving many of their men and horses strewn upon the ground.
"They twice repeated their attempt to get possession of the road and were both times repulsed by the companies under Captain Chandler. Then they threw down the fences and entered the field upon our left and opened fire upon Colonel Hogg's cavalry and the two companies of the Twentieth Ohio attached to Captain Chandler's command. The infantry and cavalry returned the fire briskly and with terrible effect. I then discovered that a full regiment of cavalry was forming in the rear of those firing upon us, with the determination of charging upon our cavalry and that portion of the infantry on the left of the road. I said to Colonel Hogg if he had any doubt about holding his position he had better fall back and not receive their charge. He promptly replied: 'Colonel Leggett, for God's sake don't order me back.' I replied, 'Meet them with a charge, Colonel, and may Heaven bless you.' He immediately ordered his men to draw their sabers, and after giving them the order to 'Forward,' he exclaimed, 'Give them cold steel, boys,' and darting ahead of his men, he fell, pierced by nine balls."
Dr. Grant A. Hogg, in a letter to William K. Baldwin, bearing date March 19th, 1900, writes: