Leonard N. Miner was born around 1819 in Canaan, New Hampshire, to Amos and Fanny Miner. His father worked as a farmer. He married Helen M. Choate on September 2, 1846, and they had at least two children: Everett, born around 1848; and Henry, born around 1850. He worked as a cabinet maker in Enfield, New Hampshire, and by 1850, he owned $400 of real estate. A decade later, he owned $1,600 of real estate and $350 of personal property.
He enlisted in the Union army on September 21, 1861, and he mustered in as a musician in Company C of the 7th New Hampshire Infantry on December 3. The regiment took part in the Battle of Fort Wagner and the siege of Petersburg. He urged his wife not to “wory about me for I am seeing no more than I expected when I enlisted & I do not mean to play the coward.” He mustered out on December 27, 1864.
He settled in Lebanon, New Hampshire, after the war, and he earned a living as a carpenter. His wife died on August 27, 1884, and he married Nellie Morse on February 17, 1887. He applied for a federal pension in March 1885, but he apparently never received one. He died in Enfield, New Hampshire, on June 21, 1890, after falling from a horse.