[4][5] The island was part of a very large property, about 50,000 acres, to which the English physician Thomas Pell established ownership in a treaty signed by five Lenape sachems in 1654.

[6][7]The island—known by different names including Minnewits, Minneford, Minefer's, Great Mulberry Island—was purchased in 1761 by Benjamin Palmer of New York, who planned to make it a major seaport in western Long Island Sound.

He went as far as to have the island mapped out in different plots designated as shipyards, docks, business, farms, homes, schools, and houses of worship, along with streets, paths, and access routes.

Benjamin Palmer appealed to the British Crown and received letters patent that covered the ownership of waterfront properties 400 feet out from the high tide mark under water and around the perimeter of the Island.

It would be another sixty years before the island again started to be developed when oystermen, pilots of Hell Gate, a set of nearby narrows, and eventually shipbuilders arrived and introduced these industries.

[3] Based on data from the 2010 United States Census, the population of Pelham Bay-Country Club-City Island was 26,583, a decrease of 557 (2.1%) from the 27,140 counted in 2000.

[18] The entirety of Community District 10, which comprises City Island, Co-op City, Country Club, Pelham Bay, Schuylerville, Throgs Neck and Westchester Square, had 121,868 inhabitants as of NYC Health's 2018 Community Health Profile, with an average life expectancy of 81.1 years.

[22] In 2018, an estimated 14% residents of Community District 10 lived in poverty, compared to 25% in all of the Bronx and 20% in all of New York City.

Based on this calculation, as of 2018[update], Community District 10 is considered high-income relative to the rest of the city and not gentrifying.

The island is most famous for its numerous seafood restaurants and antique stores, which line both sides of the avenue.

[24] In the early part of the 20th century, the area was a favored recreation location for business tycoons including Vincent Astor, J.P. Morgan and William Randolph Hearst.

The forms of animal life on the island are not much different from that of the surrounding region, and are typical of a suburban environment: raccoons, squirrels, rabbits, skunk, and occasional deer.

A small protected wetlands area on west Ditmars Street is home to many of these species as well as the feral pigeon.

Bright green parrots (monk parakeets), originally imported from South America as pets, have adapted to the climate and breed in the wild in New York.

Over 30 eating establishments compete for business, ranging from fast food (Johnny's Reef), to The Black Whale, famous for its desserts.

There are a number of old Victorian mansions located throughout City Island, mostly on the Sound side, complete with tall pointy spires and gables with gazebos, such as Delmours Point on Tier Street.

[39] A small fleet of head boats takes paying passengers on fishing trips to Long Island Sound.

The sail and power boating industry has been declining in recent years, as boatyards are being sold and being converted into condominiums.

[47] City Island is patrolled by the 45th Precinct of the NYPD, located at 2877 Barkley Avenue in Throggs Neck.

[51][52] As of 2018[update], preterm births are more common in Community District 10, which comprises City Island, Co-op City, Country Club, Pelham Bay, Schuylerville, Throgs Neck and Westchester Square, compared to other places citywide, although births to teenage mothers are less common.

In 2018, this population of uninsured residents was estimated to be 7%, lower than the citywide rate of 14%, though this was based on a small sample size.

[19]: 14 The concentration of fine particulate matter, the deadliest type of air pollutant, in Community District 10 is 0.0075 milligrams per cubic metre (7.5×10−9 oz/cu ft), the same as the city average.

[19]: 6  The percentage of Community District 10 students excelling in math rose from 29% in 2000 to 47% in 2011, and reading achievement increased from 33% to 35% during the same time period.

[56] Community District 10's rate of elementary school student absenteeism is slightly higher than the rest of New York City.

[20]: 24 (PDF p. 55) [19]: 6  Additionally, 75% of high school students in Community District 10 graduate on time, the same as the citywide average of 75%.

[57] The church operated Holy Rosary Early Childhood Academy at St. Mary Star Of The Sea until its closure in 2010.

[75][76][77] In July 1914, the IRT sold the company to the Third Avenue Railway,[78] which ceased operation of the City Island Railroad on August 9, 1919.

[80] The Bronx Tourism Council ran the City Island Seaside Trolley, which later became a ferry service.

For example: Since 2002, the film production company Harrington Talents has had its offices and studio located on City Island.

Notable celebrities who have worked on their productions include rapper and actor Ice-T, and professional wrestler Bruno Sammartino.