Jefferson County, Illinois

Jefferson County: County in Illinois, United States

About

Jefferson County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 38,827 and a population density of 26 people per km². After 10 years in 2020 county had an estimated population of 37,235 inhabitants. Its county seat is Mount Vernon. The county was created 205 years ago in 1818.

Jefferson County locator map
Location of Jefferson County on Illinois map.

Quick Facts about Jefferson County

Population : 37,235 (2020)
Country : United States of America
State : Illinois (United States)
Different from : Jefferson County, Jefferson Parish, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County, Jefferson County
Area : 1512 km2
Water as percent of area : 2.2%
Land as percent of area : 97.8%
Named for : Thomas Jefferson
Capital : Mount Vernon
Establishment : January 01, 1819
Time Zone : America/Chicago
Local time : 07:47:24 (28th March 2024)
Density : 25 Pop. per km² as of 2020
Population growth : -4.28% (2010-2020)
Jefferson County Courthouse in Mount Vernon image
Jefferson County Courthouse in Mount Vernon
Jefferson County Courthouse in Mount Vernon image

Geography

Jefferson County is located at 38°18'2"N 88°55'26"W (38.3005200, -88.9240100). It has 6 neighbors: Franklin County, Hamilton County, Marion County, Perry County, Washington County and Wayne County.

Jefferson County map

The largest city of Jefferson County is Mount Vernon with a population of 14,511. Other cities include, Woodlawn population 670, Dix population 428, Waltonville population 422 and Harmony population 263. See all Jefferson County cities & populated places.

Jefferson County Populated Places

Cities, towns, neighborhoods & other populated places in Jefferson County.

City Name Population Title
Shields 36,451 Township in Lake County, Illinois
Mount Vernon 14,511 City located near the center of Jefferson County, Illinois, United States
Spring Garden 3,208 Township in Jefferson County, Illinois
Ina 2,279 Village in Jefferson County, United States
Woodlawn 670 Community in the city of Birmingham, Jefferson County, Alabama, United States
Bluford 660 Village in the United States
Stratton 432 Township in Edgar County, Illinois
Dix 428 City in Illinois, United States of America
Waltonville 422 Human settlement in Illinois, United States of America
Bonnie 380 Village in Illinois
Belle Rive 347 Village Jefferson County, Illinois, United States
Harmony 263 Unincorporated community in Illinois
Nason 228 City in Jefferson County, Illinois

Jefferson County has 6 neighbours.

  • Mount Vernon

Demographics

According to census records, the population of Jefferson County decreased by 4.28% in 10 years.

Year Population % Change Method
2010 38,827 - census
2011 38,749 -0.2% estimation process
2012 38,658 -0.24% estimation process
2013 38,641 -0.04% estimation process
2014 38,374 -0.7% estimation process
2015 38,272 -0.27% estimation process
2016 38,214 -0.15% estimation process
2017 38,045 -0.44% estimation process
2018 37,708 -0.89% estimation process
2019 37,684 -0.06% estimation process
2020 37,235 -1.21% estimation process

Comitatul Jefferson, Comte de Jefferson, Comté de Jefferson, Condado de Jefferson, Condado han Jefferson, Contea di Jefferson, Dzhefersun, Dzhefferson, Hrabstwo Jefferson, Jefferson, Jefferson Comitatus, Jefferson Kun, Jefferson Kūn, Jefferson konderria, Jefferson megye, Jefferson srjan, Jeffersoni maakond, Okrug DZeferson, Quan Jefferson, Quận Jefferson, jefason jun, jepharasana ka'unti, jie fu xun xian, mqatʿt jyfyrswn, shhrstan jfrswn aylynwy, Джеферсън, Джефферсон, Округ Џеферсон, Ջեֆֆերսոն շրջան, جیفرسن کاؤنٹی، الینوائے, جیفرسن کاؤنٹی، الینوۓ, شهرستان جفرسون، ایلینوی, مقاطعة جيفيرسون, জেফারশন কাউন্টি, ジェファーソン郡, 傑佛遜縣

People born in Jefferson County (1)

American politician Newton R. Casey was born in Jefferson County

Other places with the same name (25)

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Kane County 531,010 County in southern Utah, United States
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Madison County 262,635 County in Montana, United States
Saint Clair County 258,046 The County of St.
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Peoria County 177,652 County in Illinois, United States of America
McLean County 171,256 County in North Dakota, United States
Naperville 147,986 The second most populous city in Illinois.