Hidden · Pea Patch Island, Delaware, United States
Fort Delaware
A pentagonal fort on a muddy island in the Delaware River that needed three designs before one stood, then held Confederate prisoners during the Civil War.
A fort built on mud, on its third design.
Fort Delaware sits on Pea Patch Island in the Delaware River. The island was soft, marshy ground, and the soil was compressible mud often forty feet deep. The first fort there was a five-pointed star designed by army engineer Joseph G. Totten, but uneven settling, badly placed piles and cracking walls delayed it for years. One section of 43,000 bricks had to be taken down, cleaned and rebuilt. A fire in 1831 destroyed much of the work, and the ruin was torn down in 1833. Its sandstone rubble went into the island's seawall, where some of it can still be seen.
A second, much larger design by Captain Richard Delafield never got built, because a legal fight over who owned the island lasted about a decade. A ruling in 1848 settled it in favor of Delaware and the United States. The present fort went up mainly between 1848 and 1860 as an irregular pentagon with five small corner bastions. Crews drove 4,911 piles into the mud with steam-powered pile drivers, and tested thousands of them before building on top. The walls are mostly gneiss, granite and brick, and more than two million bricks went into the interior. It had positions for 169 cannon, a moat and a single entrance, the sally port.
From harbor defense to Civil War prison.
During the Civil War, the Union used the fort as a prison for Confederate prisoners of war, political prisoners, civilians, federal convicts and privateer officers. It is remembered mainly for that role, and the story of the people held here deserves a quiet, serious visit.
The island kept its military job afterward. In the 1890s a three-gun concrete battery of 12-inch guns, later named Battery Torbert, was built inside the fort. By 1900 the fort worked with Fort Mott across the river in New Jersey and Fort DuPont downstream in Delaware as one of the Coast Defenses of the Delaware. Today the fort and island belong to the Delaware Department of Natural Resources and Environmental Control and form Fort Delaware State Park, which includes a living history museum.
The fort inside and out.
Practical notes.
Before you go.
Where is Fort Delaware?
On Pea Patch Island in the Delaware River, in Delaware. The island and fort are part of Fort Delaware State Park, run by the Delaware Department of Natural Resources and Environmental Control.
Why was the fort so hard to build?
The island is soft, marshy ground with mud often forty feet deep. The first fort settled unevenly and cracked, and the present one needed thousands of piles driven and tested before the walls could go up.
Was Fort Delaware a prison?
Yes. During the Civil War the Union held Confederate prisoners of war, political prisoners, civilians, federal convicts and privateer officers here.
Can you visit Fort Delaware?
It is a state park with a living history museum. Days, crossings and rules depend on the season, so check the official park page before you go.
Around Delaware
Walking tours, day trips and experiences around this area, on GetYourGuide.