Henry Rea was born on December 3, 1842 in DeGraff, Logan County, Ohio, one of the thirteen children of Jonathan and Ann Elwood Rea. On August 8, 1862, at the age of nineteen, Henry enlisted for three years as a private in the 45th OVI and on August 19 mustered into Company E, the same company as his cousin William Rea. His twin brother Jonathan had enlisted a year earlier, in August 1861, in the 20th OVI, in which he served until the end of the war, mustering out at the rank of corporal. Two other brothers also served in the Civil War -- Cyrus in the 33rd Iowa Volunteer Infantry, a three-year unit that saw heavy action in the Mississippi theater, and Benjamin in the 132rd OVI, a 100-day unit that served primarily in Virginia and North Carolina, from June to September 1864.
In the Company Descriptive Book Henry is described as being six feet tall, with blue eyes, brown hair and a dark complexion. His occupation is given as farmer.
In January 1863 Henry was detailed as a provost guard in Danville, Kentucky, but rejoined the regiment and was listed as present in the roll book all through 1863 and the first half of 1864. On February 1, 1864, he was promoted to corporal. On May 28,1864, he was wounded in the right arm and chest at New Hope Church, Georgia and was received into the field hospital the following day. He was listed as absent wounded in July, but rejoined the regiment in August.
On August 23, while writing a letter in fortifications in front of Atlanta, Georgia, he was shot and killed by an enemy bullet. His unfinished letter is in the possession of the Ohio Historical Society.