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Clay County, Florida facts for kids

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Clay County
Clay County Courthouse
Clay County Courthouse
Flag of Clay County
Official seal of Clay County
Map of Florida highlighting Clay County
Location within the U.S. state of Florida
Map of the United States highlighting Florida
Florida's location within the U.S.
Country  United States
State  Florida
Founded December 31, 1858
Named for Henry Clay
Seat Green Cove Springs
Largest community Lakeside
 • Total 644 sq mi (1,670 km2)
 • Land 604 sq mi (1,560 km2)
 • Water 39 sq mi (100 km2)  6.1%%
 • Estimate 
 • Density 352/sq mi (136/km2)
Time zone UTC−5 (Eastern)
 • Summer (DST) UTC−4 (EDT)
Congressional district 3rd

Clay County is located in the northeastern part of the U.S. state of Florida. As of 2019, the population was 219,252. Its county seat is Green Cove Springs. It is included in the Jacksonville metropolitan statistical area.


Clay County was created on December 31, 1858, from a section of Duval County. Its name is in honor of Henry Clay, a famous American statesman, member of the United States Senate from Kentucky, and United States Secretary of State in the 19th century.

Clay County was once a popular destination for tourists visiting from the northern states. The therapeutic, warm springs and mild climate were major draws for visitors. Steamboats brought them to various hotels in Green Cove Springs - the St. Elmo, Clarendon and the Oakland. President Grover Cleveland was the most prominent of such tourists; he had spring water shipped to the White House. Clay County's popularity among tourists peaked during the last three decades of the 19th century. It was later eclipsed by Henry Flagler's extension of the Florida East Coast Railway to points south such as Palm Beach and Miami.

The military has also played an important role in Clay County history. In 1939, Camp Blanding opened on Kingsley Lake in southwest Clay County. The Florida National Guard developed this 28,000 acres (110 km2) complex. During World War II, it trained over 90,000 troops and became the fourth largest "city" in the state. In Green Cove Springs, Lee Field was a flight training center. After World War II, Lee Field became a base for the mothball fleet. Although Lee Field closed in the early 1960s, Camp Blanding continues to operate today as a base for military training. Clay County is also a popular choice of residence for military personnel stationed on bases in nearby Duval County (NAS Jacksonville, NS Mayport, and, before it closed, NAS Cecil Field).


According to the U.S. Census Bureau, the county has a total area of 644 square miles (1,670 km2), of which 604 square miles (1,560 km2) is land and 39 square miles (100 km2) (6.1%) is water.

Adjacent counties



  • Keystone Heights Airport

Major highways

  • US 17
  • US 301
  • SR 16
  • SR 21
  • SR 23
  • SR 100


Historical population
Census Pop.
1860 1,914
1870 2,098 9.6%
1880 2,838 35.3%
1890 5,154 81.6%
1900 5,635 9.3%
1910 6,116 8.5%
1920 5,621 −8.1%
1930 6,859 22.0%
1940 6,468 −5.7%
1950 14,323 121.4%
1960 19,535 36.4%
1970 32,059 64.1%
1980 67,052 109.2%
1990 105,986 58.1%
2000 140,814 32.9%
2010 190,865 35.5%
2019 (est.) 219,252 14.9%
U.S. Decennial Census
1790-1960 1900-1990
1990-2000 2010-2019
Largest ancestries (2000) Percent
English England 43.5%
Irish Republic of Ireland 5.5%
German Germany 6.9%
Scottish Scotland 4.0%
"American" United States 3.8%

At the 2010 census, 190,865 people, 65,356 households, and 39,390 families resided in the county. The majority of Clay County's population was located in the northeastern region, where large suburban communities have been built. Orange Park, Middleburg, and the surrounding area specifically have the majority of the population. Green Cove Springs area has the lower population spread west and south, along with the small city of Keystone Heights, which lies at the southwestern end of the county. Although the population of Clay County is relatively high, the majority of the county is still rural and consists of many farms connected by county roads. The population density was 234 people per square mile (90/km2). The 73,208 housing units averaged 89 per square mile (35/km2). The racial makeup of the county was 81.8% White, 9.9% Black or African American, 0.5% Native American, 2.9% Asian, 0.1% Pacific Islander, 1.1% from other races, and 2.9% from two or more races. About 7.7% of the population were Hispanic or Latino, with Puerto Ricans being the majority of the Hispanic population. There were 50,243 households, 39.60% had children under the age of 18 living with them, 63.80% were married couples living together, 10.70% had a female householder with no husband present, and 21.60% were not families. Around 16.90% of households were one person and 5.50% were one person aged 65 or older. The average household size was 2.77, and the average family size was 3.11.

The age distribution was 28.00% under the age of 18, 7.90% from 18 to 24, 30.30% from 25 to 44, 24.00% from 45 to 64, and 9.80% 65 or older. The median age was 36 years. For every 100 females, there were 97.00 males. For every 100 females age 18 and over, there were 94.20 males.

The median income for a household was $48,854 and for a family was $53,814. Males had a median income of $36,683 versus $25,488 for females. The per capita income for the county was $20,868. About 5.10% of families and 6.80% of the population were below the poverty line, including 8.90% of those under age 18 and 7.40% of those age 65 or over.

According to The Florida Times-Union, as of October 2004, 106,114 voters were registered in Clay County.


  • Clay County Historical and Railroad Museum, Green Cove Springs.
  • Middleburg Historical Museum, Middleburg.
  • Black Heritage Museum, Middleburg.
  • Camp Blanding Museum, Camp Blanding.




Census-designated places

Other unincorporated communities


The Clay County School District operates 42 public schools, with currently 28 elementary schools, five junior high schools, six high schools, and one junior/senior high school.


The Clay County Public Library System consists of five branches:

  • Green Cove Springs Library
  • Headquarters Library (Fleming Island)
  • Keystone Heights Library
  • Middleburg-Clay Hill Library
  • Orange Park Library

The first public library in Clay County was made up of a small collection established by the Village Improvement Association within the county. Other small libraries were established by other organizations within Clay County. In 1961, representatives from different women's organizations in the county started a movement to establish a library system within the county, and resulted in the Clay County Board of County Commissioners beginning to set aside funds to create the county library system. Due to their efforts, the first public library in Clay County was opened in 1961 in Green Cove Springs. The Green Cove Springs Library purchased a bookmobile in 1962 and began to provide outreach services to different areas within Clay County that same year. In 1962 two more public libraries opened in Clay County, the Keystone Heights Library and the Orange Park Library. A fire destroyed the Keystone Heights Library in February 1962. The Keystone Heights Library was relocated to a new building in Theme Park in 1964. The Headquarters Library in Green Cove Springs became open to the public in 1970 after a population boom caused the need for a new library. In 1976, the Orange Park Library moved to a larger location within the town of Orange Park. The population growth experienced in the county during the late 1970s necessitated the development of the Middleburg-Clay Hill Library, which first opened in a storefront in the late 1970s. The permanent facility for this library was completed and opened to the public in 1986.

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