Fort Delaware on Pea Patch Island, was a harsh Civil War Confederate prison sometimes referred to as the "Andersonville of the North." During the course of the war, some 40,000 were held there with between 2500 and 2900 dying.
Before serving as a prison, it was a masonry fort completed in 1859, then it served as a place to train new Union troops.
After the war, it was essentially abandoned until the Spanish American War when three 16-inch cannons were installed at the south end of the island.
Following the war, it was abandoned until World War I and then left again until World War II.
In 1943, the guns were removed and the fort officially abandoned in 1944. Today it is a state park.
Finn's Point was bought by the government in the Civil War to build a battery for the protection of Philadelphia. In 1863, it became a cemetery to bury Confederate prisoners who had died at Fort Delaware. In 1910, the federal government erected an 85 foot Confederate monument in honor of the 2,436 men buried there.
A Union monument had been built in 1879 to honor the 135 soldiers who had died while on duty there.
With that many Union garrison soldiers dying, conditions must have been quite bad.
Not All Bad Prisons in the South. --Old B-Runner