Sangamon County
County
Sangamon County Courthouse in 2017
Flag Seal
Location within the U.S. state of Illinois
Illinois's location within the U.S.
Coordinates: 39°46′N 89°40′W / 39.76°N 89.66°W / 39.76; -89.66
Country	United States
State	Illinois
Founded	1821
Named for	Sangamon River
Seat	Springfield
Largest city	Springfield
Area
• Total	877 sq mi (2,270 km2)
• Land	868 sq mi (2,250 km2)
• Water	8.7 sq mi (23 km2)  1.0%
Population  (2020)
• Total	196,343
• Density	220/sq mi (86/km2)
Congressional districts	13th, 15th
Website	www.co.sangamon.il.us

Sangamon County is a county located near the center of the U.S. state of Illinois. According to the 2020 census, it had a population of 196,343.^[1] Its county seat and largest city is Springfield,^[2] the state capital.

Sangamon County is included in the Springfield, IL Metropolitan Statistical Area.

History

Sangamon County was formed in 1821 out of Madison and Bond counties. The county was named for the Sangamon River, which runs through it. The origin of the name of the river is unknown; among several explanations is the theory that it comes from the Pottawatomie word Sain-guee-mon (pronounced "sang gä mun"), meaning "where there is plenty to eat."^[3] Published histories of neighboring Menard County (formed from Sangamon County) suggest that the name was first given to the river by the French explorers of the late 17th century as they passed through the region. The river was named to honor "St. Gamo", or Saint Gamo, an 8th-century French Benedictine monk. The French pronunciation "San-Gamo" is the legacy.

Prior to being elected President of the United States, Abraham Lincoln represented Sangamon County in the Illinois Legislature. Lincoln, along with several other legislators, was instrumental in securing Springfield, the Sangamon County seat, as the state's capital. Sangamon County was also within the congressional district represented by Lincoln when he served in the US House of Representatives. Another legislator who represented Sangamon County was Colonel Edmund Dick Taylor, also known as "Father of the Greenback". The prominent financiers and industrialists Jacob Bunn and John Whitfield Bunn were based in Springfield, Sangamon County, Illinois, as well as in Chicago, during the nineteenth century and the early twentieth century. The careers of these men and the people with whom they collaborated helped to shape much of the history and development of Sangamon County, Illinois.

• 
  Sangamon County from the time of its creation to 1823
• 
  Sangamon County between 1823 and 1825
• 
  Sangamon County between 1825 and 1839
• 
  Sangamon in 1839, when the creation of Logan and Menard Counties reduced it to its present borders

Geography

According to the U.S. Census Bureau, the county has a total area of 877 square miles (2,270 km²), of which 868 square miles (2,250 km²) is land and 8.7 square miles (23 km²) (1.0%) is water.^[4]

Climate and weather

In recent years, average temperatures in the county seat of Springfield have ranged from a low of 17 °F (−8 °C) in January to a high of 87 °F (31 °C) in July, although a record low of −24 °F (−31 °C) was recorded in February 1905 and a record high of 112 °F (44 °C) was recorded in July 1954. Average monthly precipitation ranged from 1.62 inches (41 mm) in January to 4.06 inches (103 mm) in May.^[5]

Major highways

• Interstate 55
• Interstate 55 Business Loop
• Interstate 72
• U.S. Route 36
• Illinois Route 4
• Illinois Route 29
• Illinois Route 54
• Illinois Route 97
• Illinois Route 104
• Illinois Route 124
• Illinois Route 123
• Illinois Route 125

Transit

• Sangamon Mass Transit District
• Springfield station
• List of intercity bus stops in Illinois

Adjacent counties

National protected areas

• Lincoln Home National Historic Site

State protected areas

• Sangchris Lake State Recreation Area

Demographics

As of the 2010 census, there were 197,465 people, 82,986 households, and 51,376 families residing in the county.^[12] The population density was 227.4 inhabitants per square mile (87.8/km²). There were 89,901 housing units at an average density of 103.5 per square mile (40.0/km²).^[4] The racial makeup of the county was 83.6% white, 11.8% black or African American, 1.6% Asian, 0.2% American Indian, 0.5% from other races, and 2.2% from two or more races. Those of Hispanic or Latino origin made up 1.8% of the population.^[12] In terms of ancestry, 29.4% were German, 14.8% were Irish, 12.1% were English, 9.5% were American, and 6.3% were Italian.^[13]

Of the 82,986 households, 30.4% had children under the age of 18 living with them, 44.4% were married couples living together, 13.2% had a female householder with no husband present, 38.1% were non-families, and 31.8% of all households were made up of individuals. The average household size was 2.33 and the average family size was 2.94. The median age was 39.2 years.^[12]

The median income for a household in the county was $52,232 and the median income for a family was $66,917. Males had a median income of $48,324 versus $36,691 for females. The per capita income for the county was $28,394. About 9.9% of families and 13.4% of the population were below the poverty line, including 19.7% of those under age 18 and 7.3% of those age 65 or over.^[14]

Government

Sangamon County is governed by a 29-member board. Each member of the board is elected from a separate district.^[15]

Other elected officials include:^[16]

Politics

Like much of Central Illinois, Sangamon County tilts Republican. It is rather conservative for a county with an urban state capital, but is not nearly as conservative as the surrounding counties. Only six Democrats have carried it since 1896. It is slowly moving towards the Democratic camp, having shifted 8.7 points to the left since 2000 (as of 2020).