Portsmouth Naval Shipyard

Portsmouth Naval Shipyard occupies Seavey's Island and houses specialized repair facilities with multiple dry docks dedicated to nuclear submarine maintenance. The facility sits at the Maine-New Hampshire border along the Piscataqua River.

President John Adams established the facility in 1800 as one of the nation's first naval installations. During World War II, the workforce expanded to 25,000 employees building submarines.

The General Stores Building served as the site where the Treaty of Portsmouth was signed in 1905, ending the Russo-Japanese War. This diplomatic moment connects the facility to international peace efforts beyond its military purpose.

The installation employs more than 6,500 federal workers focused on overhaul and modernization work for Los Angeles and Virginia-class submarines. Access is restricted as an active military facility and requires proper authorization.

A thirty-year cleanup project received environmental clearance in 2024, removing its designation as an EPA Superfund site. This extended remediation effort ranks among the longest for American military installations.

Location: Kittery

Inception: 1800

Industry: shipbuilding

Website: https://navsea.navy.mil/Home/Shipyards/Portsmouth.aspx

GPS coordinates: 43.07889,-70.73417

Latest update: December 5, 2025 16:35