
In 1861, prisoners completed construction of Renwick's City Hospital (renamed Charity Hospital in 1870), which served both prisoners and New York City's poorer population. The Smallpox Hospital, designed by James Renwick, Jr., opened in 1856, and two years later, the Asylum burned down and was rebuilt on the same site Penitentiary Hospital was destroyed in the same fire. In 1852, a workhouse was built on the island to hold petty violators in 220 cells. The asylum, which was designed by Alexander Jackson Davis, at one point held 1,700 inmates, twice its designed capacity. By 1839, the New York City Lunatic Asylum opened, including the Octagon Tower, which still stands but as a residential building it was renovated and reopened in April 2006. In 1828, the City of New York purchased the island for $32,000 (equal to $789,624 in 2014), and four years later, the city erected a penitentiary on the island the Penitentiary Hospital was built to serve the needs of the prison inmates. Through the 19th century, the island housed several hospitals and a prison. The FDNY also maintains its Special Operations Command facility at 750 Main St. There are attempts to privatize three other buildings, including the cooperative. One rental building (Eastwood) has left New York State's Mitchell-Lama Housing Program, though current residents are still protected.

There is also a cooperative named Rivercross and a condominium building named Riverwalk. Most of the residential buildings on Roosevelt Island are rental buildings. Roosevelt Island is owned by the city but was leased to the New York State Urban Development Corporation for 99 years in 1969. It was renamed Roosevelt Island (in honor of Franklin D. It was known as Welfare Island when it was used principally for hospitals, from 1921 to 1973. The island was called Minnehanonck by the Lenape and Varkens Eylandt ( Hog Island) by New Netherlanders, and during the colonial era and later as Blackwell 's Island. On-island transport is provided by the Red Bus service. The NYC Ferry also maintains a dock on the east side of the island. The Roosevelt Island station carries the F and trains of the New York City Subway. The Roosevelt Island Tramway, the oldest urban commuter tramway in the U.S, connects the island to Manhattan Island's Upper East Side. Several public transportation options to reach the island exist.

Vehicular traffic uses the Roosevelt Island Bridge to access the island from Astoria, Queens, though the island is not designed for vehicular traffic and has several areas designed as car-free zones. Lying below the Queensboro Bridge, the island cannot be accessed directly from the bridge itself. Together with Mill Rock, Roosevelt Island constitutes Manhattan's Census Tract 238, which has a land area of 0.279 sq mi (0.72 km 2), and had a population of 11,661 as of the 2010 United States Census. Running from the equivalent of East 46th to 85th Streets on Manhattan Island, it is about 2 miles (3.2 km) long, with a maximum width of 800 feet (240 m), and a total area of 147 acres (0.59 km 2). It lies between Manhattan Island to the west, and the borough of Queens, on Long Island, to the east.

Roosevelt Island is a narrow island in New York City's East River, within the borough of Manhattan.

45% white, 27% black, 14% Hispanic, 11% Asian or Pacific Islander, and.
