John A. Logan was born around 1834 in Virginia to Richard and Mary Logan. His father was a planter who owned $6,050 of real estate and $26,510 of personal property by 1860. Logan grew up and attended school in Halifax County, Virginia, before enrolling at the University of Virginia in 1851. He studied mathematics, chemistry, and ancient and modern languages there. By 1854, he was studying law. He remained at UVA until 1855. By 1860, he was working as a lawyer in Halifax County, and he owned $1,300 of personal property.
Logan enlisted in the Confederate army on March 2, 1862, and he mustered in as a private in Company H of the 14th Virginia Infantry later that day. According to his service records, he was 5 feet, 5 inches tall, with dark hair and blue eyes. He was promoted to 1st lieutenant on May 6. He fell ill in October 1862, but he eventually recovered and rejoined the regiment. Union forces captured him on July 3, 1863, in the Battle of Gettysburg. He spent the next two years in a series of Union prisons: Fort McHenry, Fort Delaware, Johnson’s Island, and Port Lookout. He was finally released on June 12, 1865, after swearing an oath of allegiance. He died sometime after 1865.