John A. Porter was born around 1830 in Ohio. He married Elizabeth A. Smith in January 1852, and they had two children: Elsey, born on July 3, 1854; and Hannah, born in October 1857. They moved to Warsaw, Indiana, in the 1850s, and Porter worked as a farmer there.
He enlisted in the Union army on August 18, 1862, and he mustered in as a private in Company K of the 74th Indiana Infantry. The regiment took part in the Battle of Perryville, the Battle of Stones River, the Battle of Chickamauga, the Battle of Missionary Ridge, and the Atlanta campaign. He eventually earned a promotion to sergeant.
Porter remained devoted to the Union. In March 1864, he prayed that a friend would “live to enjoy the comforts of sweet liberty for which we all fight and pour out our blood so freely.” Liberty, he added, was what “our fathers died [for],” and “their sons are willing to do the same…nothing else could have induced me to leave my dear wife and children and endure the hardships of a soldiers life.” He was wounded in the right knee in the Battle of Jonesborough on September 1, 1864, and surgeons amputated his leg soon afterward. He died near Atlanta, Georgia, on September 14, 1864.