Barnum Island is located at . According to the United States Census Bureau, the CDP has a total area of, of which is land and is water.
Naming
Previously called Hog Island, after the feral pigs introduced by early European explorers to the Native Americans, it was later renamed for Sarah Ann Baldwin Barnum. It was also sometimes called Jekyl Island, after the name of the development company that bought it from the county. Between 1851 and 1870, Sarah Ann's husband Peter owned large parcels of land on Long Island, though his primary business was a Manhattan clothier. Sarah Ann arranged the purchase of Hog Island for use as a "poor farm" – a self-supporting almshouse, a social innovation for that period, and the island was renamed in her honor. Local lore connects the island's name to P.T. Barnum, the circus impresario, but this is incorrect, and likely due to confusion between "PT" and "PC". The county discontinued the almshouse and sold the island to the Jekyl Island Realty Company in 1898 for $40,000. The company renamed it Jekyl Island. The island changed hands several times in 1909, Jekyl sold it to a syndicate of developers for $120,000, who in turn sold it for $650,000 in 1911. Minimal development at that time included construction of several canals, before work was abandoned. One of those canals divides the Harbor Isle section from Island Park. New developers bought the island in 1921, and started building about 10,000 properties built in the 700 acre Island Park section in the center the island starting in 1922. It was in use as a summer resort by 1925., Island Park was incorporated as a village in 1926. The rest of the island remains unincorporated, with the western portion known as Harbor Island, and the northeastern portion retaining the name Barnum Island. However, all three make up the original Hog Island/Barnum Island, and are part of the Town of Hempstead. The entire island was flooded with two to eight feet of water and sewage by Hurricane Sandy.
Demographics
As of the census of 2000, there were 2,487 people, 836 households, and 671 families residing in the CDP. The population density was 2,631.8 per square mile. There were 854 housing units at an average density of 903.7/sq mi. The racial makeup of the CDP was 91.56% White, 0.36% African American, 0.12% Native American, 2.25% Asian, 0.04% Pacific Islander, 3.54% from other races, and 2.13% from two or more races. Hispanic or Latino of any race were 10.29% of the population. There were 836 households, out of which 26.0% had children under the age of 18 living with them, 65.3% were married couplesliving together, 10.9% had a female householder with no husband present, and 19.7% were non-families. 17.0% of all households were made up of individuals, and 6.2% had someone living alone who was 65 years of age or older. The average household size was 2.86 and the average family size was 3.16. In the CDP, the population was spread out, with 18.0% under the age of 18, 7.2% from 18 to 24, 28.4% from 25 to 44, 32.6% from 45 to 64, and 13.8% who were 65 years of age or older. The median age was 42 years. For every 100 females, there were 97.5 males. For every 100 females age 18 and over, there were 93.8 males. The median income for a household in the CDP was $79,656, and the median income for a family was $82,742. Males had a median income of $56,563 versus $37,727 for females. The per capita income for the CDP was $33,498. About 9.1% of families and 10.8% of the population were below the poverty line, including 18.1% of those under age 18 and 12.4% of those age 65 or over.
Nunley's Ferris wheel, formerly located at Nunley's Carousel and Amusement Park on the Baldwin-Freeport, New York border, is now located in Barnum Island, in Baldwin, New York. Nassau County purchased Nunley's Carousel in 1995, restored it, and reopened it in 2009 at the Cradle of Aviation Museum in Garden City, New York. Other Nunley's rides and games were sold at auction after the park closed in 1995 and are now scattered all over the country.
