Fort Knox, now Fort Knox State Park or Fort Knox State Historic Site, is located on the western bank of the Penobscot River in the town of Prospect, Maine, about from the mouth of the river. Built between 1844 and 1869, it was the first fort in Maine built entirely of granite; most previous forts used wood, earth, and stone. It is named after Major General Henry Knox, the first U.S. Secretary of War and Commander of Artillery during the American Revolutionary War, who at the end of his life lived not far away in Thomaston. As a virtually intact example of a mid-19th century granite coastal fortification, it was added to the National Register of Historic Places in 1969 and declared a National Historic Landmark on December 30, 1970. Fort Knox also serves as the entry site for the observation tower of the Penobscot Narrows Bridge that opened to the public in 2007. History Background Local memory of the humiliation of Maine at the hands of the British during the American Revolution and again during the War of 1812 contributed to subsequent anti-British feeling in Eastern Maine. The Penobscot Expedition of 1779 aimed to force the British from New Ireland (Maine), but ended in a debacle. The Americans lost 43 ships and suffered approximately 500 casualties in the worst naval defeat for the United States prior to the Japanese attack on Pearl Harbor. Then in autumn 1814, during the War of 1812, a British naval force and soldiers sailed up the Penobscot and defeated an outnumbered American force in the Battle of Hampden. The British followed their victory by looting both Hampden and Bangor. The American defeat contributed to the post-war movement for Maine's statehood, which occurred in 1820, as Massachusetts had failed to protect the region. The Aroostook War of 1838-1839 revived anti-British feeling and concern over the vulnerability of the region to another attack like that of 1814. Also, the Penobscot valley and Bangor were major sources of shipbuilding lumber. The response was the inclusion of the Penobscot in the Third System of coastal fortifications, and the construction of Fort Knox, a large, expensive, granite fort at the mouth of the Penobscot River. Construction Construction began in 1844 and continued until all masonry fort funding was withdrawn in 1869, with the fort mostly complete except for the emplacements on the "roof" or barbette level. Funding from Congress