History
St. Johns County was created in 1821. It was named for St. John the Baptist.
Geography
The county has a total area of 2,127 km2 (821 mi2). 1,577 km2 (609 mi2) of it is land and 550 km2 (212 mi2) of it is water. The total area is 25.86% water.
Demographics
As of 2000, there are 123,135 people, 49,614 households, and 34,084 families residing in the county. The population density is 78/km2 (202/mi2). There are 58,008 housing units at an average density of 37 persons/km2 (95 persons/mi2). The racial makeup of the county is 90.92% White, 6.29% African American, 0.26% Native American, 0.95% Asian, 0.05% Pacific Islander, 0.55% from other races, and 0.97% from two or more races. 2.63% of the population are Hispanic or Latino of any race.
There are 49,614 households out of which 29.20% have children under the age of 18 living with them, 56.80% are married couples living together, 8.90% have a woman whose husband does not live with her, and 31.30% are non-families. 24.30% of all households are made up of individuals and 9.40% have someone living alone who is 65 years of age or older. The average household size is 2.44 and the average family size is 2.90.
In the county the population is spread out with 23.10% under the age of 18, 7.00% from 18 to 24, 27.60% from 25 to 44, 26.40% from 45 to 64, and 15.90% who are 65 years of age or older. The median age is 41 years. For every 100 females there are 94.50 males. For every 100 females age 18 and over, there are 91.50 males.
The median income for a household in the county is $50,099, and the median income for a family is $59,153. Males have a median income of $40,783 versus $27,240 for females. The per capita income for the county is $28,674. 8.00% of the population and 5.10% of families are below the poverty line. Out of the total people living in poverty, 9.30% are under the age of 18 and 6.20% are 65 or older.