Henry A. Caldwell was born around 1835 in Ohio to Francis and Catherine Caldwell. His father was a farmer who owned $7,000 of real estate and $500 of personal property by 1860. He grew up and attended school in Polk, Ohio, and he married Henrietta Chase on February 16, 1857. They had at least seven children: Florence, born around 1858; Frank, born around 1860; Sarah, born around 1862; Lorenzo, born around 1865; Walter, born around 1869; Nora, born around 1872; and Michael, born around 1876. They lived in Polk, and Caldwell worked as a farmer. By 1860, he owned $600 of real estate and $500 of personal property.
Caldwell enlisted in the Union army on November 6, 1861, and he mustered in as a private in Company H of the 64th Ohio Infantry later that day. He may have mustered out soon afterward. They moved to Congress, Ohio, sometime before 1880, and his wife died in 1896. By 1900, he was living in his son Frank’s household in Bloomfield, Ohio, and he was working as a day laborer. He died in Morrow County, Ohio, on April 25, 1918.