Built in 1872 and known then as the Blackwell Island Lighthouse, the fifty-foot-tall stone lighthouse at the northern tip of Roosevelt Island was built, if the legends can be believed, by the deranged occupants of a nearby insane asylum. But what’s not in doubt is that it was built by the city as a navigation aid for boats avoiding the rocks in the so-called “Hell Gate” waters.
The legends of its origin are recounted on a sign that was once posted at the lighthouse:
“The legendary mysteries are the names of Asylum inmate(s?) John McCarthy and Thomas Maxey and whether these two names refer to one person, two people, or even existent people. Supposedly, before the lighthouse was built, McCarthy (or Maxey), fearing a British invasion, was constructing a four-foot-high clay fort on this site. Asylum officials let him finish the fort because, during his adrenaline-rushed work, he reclaimed significant areas of marsh. (They even gave him old Civil War cannons as encouragement.) When the city wanted to build the Lighthouse, officials bribed or persuaded McCarthy either to give up or to demolish the fort.
Whether McCarthy complied or not is the choice of the storyteller, but the fort did come down. Then, supposedly, another asylum patient was summoned to build the lighthouse. This inmate styled himself ‘Thomas Maxey, Esq., architect, mason, carpenter, civil engineer, philosopher, and philanthropist.’ The lighthouse was built, though adherence to Renwick’s blueprint is questionable. Despite Thomas Maxey’s supposed labor, John McCarthy’s name was credited on a plaque that remained at the Lighthouse’s base until its mysterious disappearance in the 1960s:
‘This work was done by John McCarthy who built the lighthouse from the bottom to the top all ye who do pass by may pray for his soul when he dies.’”
The lighthouse was listed on the National Register of Historic Places in 1972 and made a New York City Landmark in 1976.