Located inside the Odiorne Point State Park, Fort Dearborn is a WWII armed forces station, built to protect the Portsmouth Harbor better. Before that, the area was just an expensive waterfront land which is also known to be a part of the New Hampshire Sunken Forests series.

Fort Dearborn was completed in 1943. It consisted of a number of structures, many of which were platforms for big firearms.

The park opened in 1962, after the property was sold back to the state of New Hampshire. Most of the military structures were demolished, and only a few remained to be used by the park. Initially, it was named ?Fort Dearborn State Park?, but since the state decided to focus more on the natural history of the area, it was renamed to ?Odiorne Point State Park?.