Portsmouth Harbor Light In 1771, there was a pole with a lantern hung on it, that was the first lighthouse at Fort William and Mary, the British stronghold on Newcastle Island that guarded Portsmouth Harbor. Paul Revere rode to Portsmouth from Boston with news that the British had made plans to strengthen the fort. The colonists, being forewarned overtook the fort and made off with the supplies. A more permanent tower was erected between 1782 and 1784, which made it one of the 12 colonial lighthouses of America. A new octagonal tower was erected in 1804 and was replaced with a 48 foot cast iron tower in 1877. And a fourth order Fresnel lens was installed. In 1960 the light was automated and is now part of the Ft.Constitution Historic Site.