Milo T. Hardy was born around 1841 in Hollis, New Hampshire, to Truman and Ellen Hardy. His father was a grocer who owned $700 of real estate and $2,000 of personal property by 1860. The family lived in Manchester, Massachusetts, and by 1860, he was working as a clerk.
He enlisted in the Union army on September 15, 1862, and he mustered in as a private in Company A of the 45th Massachusetts Infantry on September 26. The regiment was deployed to North Carolina, and it took part in the Battle of Kinston. He mustered out on July 7, 1863.
He settled in Newbury, Ohio, after leaving the army, and he married Melissa H. Ober on February 24, 1866. They had at least four children: Etta, born around 1869; Clara, born around 1870; Eva, born around 1874; and Laverne, born around 1876. He earned a living as a farmer. By 1870, he owned $1,000 of real estate and $400 of personal property. His wife died on January 2, 1911, and he married Sarah J. Swift on March 13, 1912. He died of pneumonia in Douglasville, Georgia, on December 30, 1919.