It was originally called Littleton Island.
It has a U.S. Army missile tracking station built during the Cuban missile crisis In 1960. The station flies a white radar aerostat, known locally as "Fat Albert," that runs a drug interdiction mission for the Drug Enforcement Administration. On April 20, 2007 a Cessna 182 crashed after its left wing struck the tether anchoring Fat Albert The aerostat is marked on air navigation charts inside a restricted area that contains the warning, "Caution: Unmarked balloon on cable to 14,000 [feet]."
Possibly named for the Joewood tree (Jacquinia keyensis Mez), a native species which is also known as cudjoewood. A more likely derivation for the name is offered by writer John Viele of Summerland Key. He believes that Cudjoe, which is a very common West African name, was the name of a runaway or freed black who lived on the island at some point prior to Gerdes' survey in 1849.
There were 799 households out of which 15.6% had children under the age of 18 living with them, 62.0% were married couples living together, 3.4% had a female householder with no husband present, and 32.2% were non-families. 21.7% of all households were made up of individuals and 7.8% had someone living alone who was 65 years of age or older. The average household size was 2.12 and the average family size was 2.43.
In the CDP the population was spread out with 12.2% under the age of 18, 3.7% from 18 to 24, 27.1% from 25 to 44, 38.8% from 45 to 64, and 18.2% who were 65 years of age or older. The median age was 48 years. For every 100 females there were 108.2 males. For every 100 females age 18 and over, there were 109.4 males.
The median income for a household in the CDP was $57,500, and the median income for a family was $59,883. Males had a median income of $36,094 versus $31,250 for females. The per capita income for the CDP was $27,085. About 4.4% of families and 5.8% of the population were below the poverty line, including 5.7% of those under age 18 and 5.4% of those age 65 or over.