Fort Delaware was initially constructed in the mid-1800s to protect Wilmington and Philadelphia from enemy attack. Fort Delaware served that role through WWI. The fort was among the most state-of-the-art in the nation when it was completed and housed prisoners of war during the Civil War due to its relative isolation. Click on an image below to increase the size, then use your forward or backward key on your computer or the icon on the right or left of the picture to go to the following picture.