Smallpox was one of the most dangerous diseases before science progressed and the vaccine was invented. The story of Smallpox Hospital on Roosevelt Island begins at that time. In New York City, the southern tip of Blackwell’s Island (now Roosevelt Island) provided ferry access but kept the infected patients far away from the population. Better known for Grace Church on Broadway and St. Patrick’s Cathedral on Madison Avenue, James Renwick Jr. designed the smallpox hospital in his Gothic Revival style. From 1856 until 1875, the hospital treated about 7,000 patients a year. In 1875, the building was converted into a nurses’ dormitory, and the city smallpox hospital was moved to North Brothers Island, in part because Blackwell’s Island had become more densely populated. By the 1950s, Renwick Hospital had become useless and was abandoned by the city, quickly falling into disrepair.