John Milton Summers was born on April 25, 1841, in Delaware County, Indiana, to John Summers and Lydia Meliza. His father was a doctor who owned $6,500 of real estate and $1,500 of personal property by 1860. His mother died sometime during his childhood. By 1860, the family was living in Liberty, Indiana. He enlisted in the Union army on October 30, 1862, and he mustered in as a private in Company G of the 54th Indiana Infantry later that day. He was discharged for disability on December 8, 1862.
He returned to Indiana after leaving the army, and he married Martha Pumphrey there on August 13, 1863. They had at least three children: Larkin, born around 1865; John, born around 1867; and Allie, born around 1869. They lived in Wildcat, and Summers worked as a farmer. By 1870, he owned $3,000 of real estate and $100 of personal property. He applied for a federal pension in June 1891 but apparently never secured one. Martha died of a “dropsical trouble” on July 21, 1904. He married Elizabeth Hinshaw on December 18, 1906. He died in Tipton County, Indiana, on April 9, 1928.