John Palmer Barnum, son of Zar Barnum, was a Civil War soldier who enlisted on 6 Aug 1862. He served with Company "E", 18th Michigan and was captured by the Confederates on 24 September 1864 at the Battle of Sulphur Creek Trestle, also known as the Battle of Athens, which was fought near Athens, Limestone, Alabama. He was interned at the Cahaba Prison Camp.
Cahaba prison was located near Selma, Alabama, in the center of the now-vanished town of Cahawba which was the state capital of Alabama from 1820 to 1826. The prison was located in a cotton warehouse on the banks of the Alabama River and was in operation intermittently from 1862 to April 1865. More than 9,000 men were imprisoned at Cahaba over that time period. At its peak in 1864 and 1865, 3,000 men were housed there in with an average living space of only six square feet, by far the most crowded of any prison, north or south. Conditions were harsh, but thanks to a humane prison director and the kindnesses of town people, fewer than 250 soldiers died there. Over 800 men who had been imprisoned at Cahaba perished in the Sultana Disaster on April 27, 1865.
John was killed at Memphis, Tennessee, 27 Apr 1865, in the explosion of the steamship "Sultana" which was loaded with Union prisoners of war scheduled to be exchanged for Confederate prisoners held by the Union army.
On 24 Apr 1865, the Sultana, a sidewheeler designed to carry about 400 passengers, had left Vicksburg, Mississippi, for Cairo, Illinois, with about 2,100 Federal prisoners crammed onto its decks. Most of them had been interned at the infamous Andersonville Prison Camp before it was closed down. The steamboat was in terrible mechanical shape.
Outside Memphis, early on the morning of the 27th while the men were asleep, a boiler exploded and the ship caught fire. An eyewitness recalled that the passengers were jumping into the water until it was "black with men" but many were so weak from starvation and disease that they were unable swim to shore. Many others did not know how to swim, and stayed on the decks with the fire raging around them. The Sultana burned for about six hours before it sank. At sunrise rescuers found survivors clinging to everything imaginable, "even dead bodies". For weeks bodies were pulled from the Mississippi, as far away as Helena, Arkansas.
In that one incident, about 1,700 men who had survived the unspeakable horrors of the prison camps perished on their way home to the Midwest.