Henry R. Hess was born around May 1841 in New York to Jacob and Margaret Hess. His father was a farmer who owned $3,600 of real estate by 1850. He grew up and attended school in Pulteney, New York, and by 1860, he was working as a farm laborer.
He enlisted in the Union army on August 25, 1862, and he mustered in as a private in Company A of the 161st New York Infantry on September 18. He fell ill in December 1862, and army officials sent him home to recover. He returned to duty on April 30, 1863. The regiment took part in the siege of Port Hudson, the Red River campaign, and the Mobile campaign, and Hess mustered out on October 17, 1865.
Hess returned to Pulteney after the war, and he married a woman named Anna around 1871. They had at least two children: Henry, born around 1887; and May, born around 1879. He worked as a grape grower and farmer. His wife died in the early 1900s, and he passed away in Pulteney on October 21, 1913.