Charles Denny was born on December 25, 1759, in Pauldingstown, Dutchess County, New York.

In the early summer of 1777 while residing in the town of Armenia, New York, at the age of 18 Charles Denny served a three-month term as a substitute for his father, John Denny. He served in a company commanded by Captain Noah Wheeler and Lieutenant Seth Wheeler.

The company was marched to West Point, where the men were engaged for their three-month term in the digging of what was called the "Bomb Proof" at the fort. Charles also served as the company cook near the close of the term. At the end of the term, the men were discharged and Charles Denny returned to Armenia.

In July 1778 Charles Denny again was engaged as a substitute in a company commanded by Captain Seth Wheeler in the regiment commanded by Colonel Roswell Hopkins and Major Brenton Paine.

The regiment was moved to Fishkill Flats, almost directly opposite West Point on the Hudson River, serving as reconnaissance and reserve in case of an attack on West Point. At the close of this three-month term Charles Denny was again discharged and returned to his home in Armenia, New York.

In July 1779, Charles Denny yet again went as a substitute again in a company commanded by Noah Wheeler in Colonel Roswell Hopkins’. regiment. The regiment was once again stationed at Fishkill Flats, and remained here until the first snow fell in the fall of 1779. He received a written discharge and returned to his home in Armenia.

In August 1780 Charles Denny went to West Point as a substitute for William Wilsey for a term of eight days in a company commanded by the Wheeler brothers. This tour lengthened to 14+ days, as the British ship HMS Vulture had appeared off West Point. During this time at West Point there was "so much hurry and confusion it was difficult to ascertain what officers were in command."

The HMS Vulture, a Sloop of War, was a large ship, approximately 100 feet long, with a full quota of guns.

The initiative of a small group of New York militia with a cannon on the heights overlooking the river were able to bombard the Vulture. The British vessel was unable to move due to the tides and winds and by the time both had changed and the ship was able to sail out of range, it was badly damaged.

It was with the driving off of the HMS Vulture that began the unraveling of Benedict Arnold’s intended treason and prevented disaster for the American side.

Despite the "hurry and confusion" Charles Denny clearly recalled seeing General George Washington and Generals Putnam and Arnold at this time at West Point. It was later in 1780 that Benedict Arnold’s treason would be exposed.

At the end of this expedition, Charles Denny was once again discharged and returned to Armenia where he remained a few years.

At the end of the war, Charles Denny relocated to Stephentown in Brewster County New York and lived there for 7 years. He then returned to Dutchess County for about 1 year, then moved to near Albany on the Hudson River and remained there about 14 years. From here he moved to Cherry Valley, New York and remained here one year. He went back to Dutchess County for about a year and then went to Greene County, New York and stayed here for 5 or 6 years. He then went to Boone County and stayed here 2 years. He then moved to Sheridan, Chautauqua County, New York. It was here that on July 10, 1833 that Charles Denny applied for a pension. He was placed on the pension rolls at the rate of $31.66 per annum.

By February 1838 Charles Denny had relocated to Illinois to live with his children. He died on August 6, 1839 aged 79 years, 7 months and 11 days. He is buried in the Pioneer Cemetery in Mokena, Will County, Illinois.