Camp Dennison was one of the largest training camps of the Civil War. Named for Governor William Dennison, the site was selected by William S. Rosecrans as a replacement for Camp Harrison, which, due to its close proximity to Cincinnati, was less than ideal for training men without the distractions of family, alcohol, and loose women close by. The site selected for Camp Dennison occupied about 700 acres on either side of the Little Miami Rail Road, being sixteen miles from the depot in Cincinnati. The distance to the camp from Cincinnati then would serve as a deterrent to those who might otherwise have set up businesses that would have tempted the young men assembling for war. At its peak the camp could hold 12,000 recruits, and after the battle of Shiloh, the camp would also serve as a major hospital facility, with eventually enough beds to hold over 2,000 sick and wounded.
Recently I was able to obtain a letter written on January 18th, 1862 (160 years to the day this post was first published) by Winfield Scott Sherman who was serving in Company L of the Second Ohio Cavalry Regiment. Born on April 19th, 1839 in Lake County, Ohio, Sherman would first enlist in the Twelfth Pennsylvania Volunteer Infantry on April 25th, 1861 as part of the rush to the colors shortly after the Confederate guns fired on Fort Sumter. The Twelfth was a three month regiment, and would muster out of service on August 5th. Sherman had not seen enough military service to satisfy his eagerness to put down the rebellion, and so he would enlist again in Ohio on September 1st, and muster into the Second Ohio Cavalry on October 10th. The Second was an incredible unit, as seen by the many skirmishes and battles shown on its regimental colors. It would also have sixth Medal of Honor recipients in its ranks.
Sherman's company began its organization at Camp Wade near Cleveland, and would move to Camp Dennison in January 1862. From Camp Dennison Sherman would write the following letter to his brother, whom I believe was Thomas Corwin Sherman, who would join the Second Ohio Cavalry on March 8th, 1864.
Camp Dennison, Ohio.
Jan. 18th, 1862
Your letter of the 21st ult. reached me in due time. I should have answered it sooner, but we were about to leave Camp [Wade?] and I put off writing till we should reach this [camp}. The regiment commenced arriving by squadrons on the 13th inst. There are now four squadrons, or eight companies here, and four companies or two squadrons to come. Monday morning will bring the last in. We marched to Shelby, a distance of 28 miles and thence to this place by rail. The horses were carred [sic], and the baggage put in baggage cars, the men in passenger cars, making in all a train of some twenty cars. We had quite [a] pleasant time coming here. The men were anxious to move, and were in fine spirits and some of them considerably under the influence of spirits.
Camp Dennison is located fifteen miles north of Cincinnati, Ohio. The camp encloses about one thousand acres of land, on the south bank of the little Miami River. There is nothing grand or romantic about the location of the camp.
There are now in this camp about seven thousand men, being three regiments of cavalry, six infantry and some artillery. The whole of them out on drills or parade will make a fine appearance. We have been here but two days and my time had been so much occupied that I have seen but little of the other regiments or of the camp. The weather too has been bad, and the camp very muddy. A few days more and I will be to see none. I know not how long we shall stay here, or where we shall go. There is some probability of going to Texas. Should we go there, I shall be on hand [to] deal out vengeance to some of the hell hounds who exiled me from there in 1860 and if I can I shall try to enrich myself at their expense as much as they impoverished me where there. I enjoy soldier life much and think I shall continue to do so.
Brother John is on the Potomac, near Washington. I have not heard from him. Give me his address. I want to write him immediately. 
We have not received any pay as yet. I think we will receive some next week.
Remember me to all inquiring friends.
Winfield Scott Sherman would survive the war and marry Anna Eliza Palmer on July 19th, 1866. From that marriage would pass away on December 20th, 1915 at the age of seventy-six. He is buried with his wife in the High Ridge Cemetery, Gentry County, Missouri.
 "Brother John" is John Y. A. Sherman, who was serving in the Eighty-First New York Volunteers. John would die on October 15th, 1862.