John H. Cooper was born around 1840 in Ohio to William and Catherine Cooper. His father was a farmer who owned $4,000 of real estate and $900 of personal property by 1860. The family lived in Lima, Ohio, and by 1860, Cooper was working as a farmer.
He enlisted in the Union army on July 18, 1861, and he mustered in as a sergeant in Company C of the 27th Ohio Infantry four days later. The regiment took part in the siege of Corinth, the Battle of Iuka, the Atlanta campaign, the March to the Sea, and the Carolinas campaign. He was wounded at Corinth on May 28, 1862, but he eventually recovered and rejoined the regiment. He was promoted to 2nd lieutenant on March 19, 1863, to 1st lieutenant on May 9, 1864, and finally to captain on November 3, 1864. He mustered out in Louisville, Kentucky, on July 11, 1865.
Cooper returned to Ohio after the war, and he married Mary Mason on November 30, 1865. They had five children: Charles, born around 1869; Otto, born around 1874; Margaret, born around 1876; Laura, born around 1879; and Edward, born around 1884. They lived in Pataskala, Ohio, and Cooper worked as a grocer. By 1870, they owned $500 of personal property. They moved to Jackson, Ohio, in the 1870s, and then to St. Louis, Missouri, in the late 1800s. He applied for a federal pension in August 1879 and eventually secured one. He died in Columbus, Ohio, on November 19, 1915.