Vermilion County is a county in the eastern part of the U.S. state of Illinois, between the Indiana border and Champaign County. It was established in 1826 and was the 45th of Illinois' 102 counties. According to the 2020 United States census, it had a population of 74,188. It contains 21 incorporated settlements; the county seat and largest city is Danville.

Vermilion County is part of the Danville, IL Micropolitan Statistical Area, as well as the larger Champaign–Urbana–Danville Combined Statistical Area.

Vermilion County is named after the Vermilion River, which passes through the county and empties into the Wabash River in Indiana near Cayuga; the river was so named because of the color of the earth along its route.

The area which became Vermilion County was under the flag of France from 1682 to 1763, as part of New France.

It was taken over by Great Britain for fifteen years after the French and Indian War; it then became part of the colonies after the Revolutionary War when the area was ceded to Virginia, titled "the Illinois County of Virginia". Later it was part of the Indiana Territory, then the Illinois Territory, and finally the state of Illinois. The county was created on January 18, 1826, from a portion of Edgar County. There was an unorganized territory to the north and west which was attached to the county; Champaign and Iroquois counties were formed from part of this territory in 1833. The remainder was used to create Ford County in 1859, the last Illinois county to be formed.

The county's saline springs were a strong attraction to early explorers; they were mentioned as early as 1801. Joseph Barron, an interpreter fluent in several Native American languages, stated in an affidavit that he was present at the "Vermilion Salines" that year. The production required 100 gallons of water for one bushel of salt and proved to be profitable from the first run (1822–1829), when salt became less expensive and the venture was no longer economical.

The area's first settlement was made in 1819 near these saline springs, by the Treat, Beckwith, and Whitcomb. James Butler, from Ohio, followed in 1820 and settled in the Catlin area; within a few years, the settlement grew to encompass several families and became known as "Butler's Point". In the southern part of the county, Henry Johnson built a cabin west of present-day Georgetown; this area was known as "Johnson's Point". The southern portion of the county was soon filled with small settlements. Most settlers in Vermilion County came from the American South, who had left because of their opposition to slavery.

Some of the early settlers were of the Religious Society of Friends, or Quakers. They founded the settlement of Vermilion Grove in the south part of the county, one of the county's first settlements and the site of the county's second public school.

The county has strong ties to Abraham Lincoln, who practiced law in Danville from 1841 to 1859 with Ward Hill Lamon; Lamon later served as Lincoln's bodyguard. Lincoln spoke in Danville during his 1858 campaign for a seat in the US Senate. Lincoln gave the speech in his stocking feet from the balcony of Dr. William Fithian, a prominent local physician. The Fithian home is now listed on the National Register of Historic Places and serves as the Vermilion County Museum; visitors can see Lincoln memorabilia including a bed in which Lincoln slept.

The various stages in the evolution of Vermilion County are shown below.

• 
  Vermilion County from the time of its creation to 1831, including a large tract of unorganized territory temporarily attached to it.
• 
  Vermilion between 1831 and 1833
• 
  The county between 1833 and 1836, after creation of Champaign and Iroquois Counties
• 
  Vermilion County between 1836 and 1837
• 
  Vermilion County between 1837 and 1853
• 
  Vermilion County after 1853, when the unorganized territory was reduced to its current size.
• 
  In 1859, the additional territory was split off as Ford County, reducing Vermilion to its current borders.

Vermilion County is located along the eastern border of Illinois; its northern border is about 95 miles (153 km) south of Chicago.

Vermilion County in Illinois and Vermillion County in Indiana are two of twenty-two counties or parishes in the United States with the same name to border each other across state lines. According to the 2010 census, the county has a total area of 901.28 square miles (2,334.3 km), of which 898.37 square miles (2,326.8 km) (or 99.68%) is land and 2.91 square miles (7.5 km) (or 0.32%) is water. The land in Vermilion County consists mostly of various forms of silt loam. Lake Vermilion, a man-made 1,000-acre (400 ha) reservoir, is the county's largest body of water, located northwest of Danville. It provides the city's culinary water, and also provides recreation opportunities.

• Danville (county seat)
• Hoopeston
• Georgetown

Several towns were established in the county which no longer survive. In some cases, the coming of the railroads helped to define the best locations for settlements, and as a result some existing towns were abandoned. When Lake Vermilion was created, the town of Denmark was flooded and now lies at the bottom of the reservoir.

Township government was adopted in Vermilion County on November 5, 1850, and eight townships were created:

Eleven additional townships were created in the following decades:

The Vermilion County Conservation District operates four parks:

• Forest Glen Preserve
• Heron County Park
• Kennekuk Cove County Park
• Lake Vermilion County Park

The Illinois Department of Natural Resources manages three areas in the county:

• Kickapoo State Recreation Area
• Harry "Babe" Woodyard State Natural Area
• Middle Fork State Fish and Wildlife Area

Historical population

Census	Pop.	Note	%±
1830	5,836		—
1840	9,303		59.4%
1850	11,492		23.5%
1860	19,800		72.3%
1870	30,388		53.5%
1880	41,588		36.9%
1890	49,905		20.0%
1900	65,635		31.5%
1910	77,996		18.8%
1920	86,162		10.5%
1930	89,339		3.7%
1940	86,791		−2.9%
1950	87,079		0.3%
1960	96,176		10.4%
1970	97,047		0.9%
1980	95,222		−1.9%
1990	88,257		−7.3%
2000	83,919		−4.9%
2010	81,625		−2.7%
2020	74,188		−9.1%
2023 (est.)	71,652		−3.4%
US Decennial Census

As of the 2010 United States Census, there were 81,625 people, 32,655 households, and 21,392 families residing in the county. The population density was 90.9 inhabitants per square mile (35.1/km). There were 36,318 housing units at an average density of 40.4 per square mile (15.6/km). The racial makeup of the county was 82.5% white, 13.0% black or African American, 0.7% Asian, 0.2% American Indian, 1.5% from other races, and 2.2% from two or more races. Those of Hispanic or Latino origin made up 4.2% of the population. In terms of ancestry, 21.2% self-identified as American, 18.9% as German, 10.1% as Irish, and 9.1% as English.

Of the 32,655 households, 31.4% had children under the age of 18 living with them, 45.7% were married couples living together, 14.7% had a female householder with no husband present, 34.5% were non-families, and 29.8% of all households were made up of individuals. The average household size was 2.41 and the average family size was 2.96. The median age was 39.8 years.

The median income for a household in the county was $39,456 and the median income for a family was $49,429. Males had a median income of $40,107 versus $30,104 for females. The per capita income for the county was $20,218. About 14.6% of families and 18.7% of the population were below the poverty line, including 30.0% of those under age 18 and 9.1% of those age 65 or over.

Danville, Illinois
Climate chart (explanation)
J F M A M J J A S O N D     2.1     34 17     2     40 22     3.2     52 32     3.9     65 41     4.5     75 51     4.7     84 60     4.4     86 64     3.9     84 63     3     78 55     3     67 43     3.5     52 34     2.8     39 23 █ Average max. and min. temperatures in °F █ Precipitation totals in inches Source: The Weather Channel
Metric conversion J F M A M J J A S O N D     52     1 −8     51     4 −6     81     11 0     98     18 5     114     24 11     119     29 16     112     30 18     100     29 17     77     26 13     77     19 6     90     11 1     71     4 −5 █ Average max. and min. temperatures in °C █ Precipitation totals in mm

Vermilion County is in the humid continental climate region of the United States along with most of Illinois. Its Köppen climate classification is Dfa, meaning that it is cold, has no dry season, and has a hot summer. In recent years, average temperatures in Danville have ranged from a low of 17 °F (−8 °C) in January to a high of 86 °F (30 °C) in July, although a record low of −26 °F (−32 °C) was recorded in January 1994 and a record high of 112 °F (44 °C) was recorded in July 1936. Average monthly precipitation ranged from 1.99 inches (51 mm) inches in February to 4.70 inches (119 mm) inches in June.

Danville Mass Transit provides public transit to the Danville area with buses.

• Interstate 74 enters Vermilion County from the west on its way from Champaign–Urbana, and passes just to the north of the towns of Fithian, Muncie and Oakwood before passing through the south edge of the Kickapoo State Park, the north edge of Tilton and the south edge of Danville. Continuing east, it leaves the county and the state on its way to Indianapolis.
• US Route 136, which runs across five states, passes into Vermilion County from the west on its way from Rantoul. It passes east through the towns of Armstrong, Potomac and Henning; it reaches Illinois Route 1 south of Rossville and then shares that highway's route as it passes south through Danville. At the south edge of Danville it reaches Main Street and resumes its eastward heading, leaving the east edge of Danville and passing out of the county and state on its way to Covington, Indiana.
• US Route 150 enters the county from Champaign–Urbana to the west, running just to the south of Interstate 74 and passing through the towns of Fithian, Muncie and Oakwood. Just west of Danville it crosses to the north side of Interstate 74 as that highway veers to the southeast. In downtown Danville, it meets Illinois Route 1 and U.S. Route 136, and follows Route 1 to the south and continues through the towns of Belgium, Westville, Georgetown and Ridge Farm before entering Edgar County further to the south.
• Illinois Route 1 runs from the north to the south through the county, passing through Hoopeston, Rossville, Danville, Belgium, Westville, Georgetown and Ridge Farm.
• Illinois Route 9 runs from west to east near the north edge of the county and passes through Rankin and Hoopeston; upon reaching the Indiana border
• Indiana State Road 26 continues its route to the east toward Lafayette, Indiana.
• Illinois Route 49 is a north–south highway near the western edge of the county. It passes south through Rankin where it intersects Route 9; further south it passes near Armstrong where U.S. Route 136 briefly shares its route. Crossing Interstate 74, it shares the route of U.S. Route 150, running west for about 2 miles (3.2 km) and leaving the county before continuing south in Champaign County.
• Illinois Route 119 is a short 8-mile (13 km) east–west road that connects the intersection of Illinois Route 1 and U.S. Route 136 with Indiana State Road 28 at the state line.

Four railroad lines pass through or into the county, all intersecting in the Danville area; this results in many different railroad crossings throughout the city:

• Norfolk Southern Railway line – enters the county from Decatur to the southwest and passes through Danville on its way to Lafayette, Indiana to the northeast
• CSX Transportation line - north-south through the county, connecting Chicago and Terre Haute, Indiana via Paris
• Kankakee, Beaverville and Southern Railroad line – north–south line through the county, to the east of the CSX line, a few miles from the state border, beginning in northern Iroquois County and running south through Danville, then veering east.
• Vermilion Valley Railroad line – a 6-mile (9.7 km) line that connects the Flex-N-Gate factory west of Covington, Indiana with CSX in Danville.

The Vermilion Regional Airport is located northeast of Danville.

For 2014, Vermilion County had a workforce of 35,643 people; 32,584 were employed and 3,059 (8.6%) were unemployed.

There are 12 school districts in the county that provide primary and secondary education. There are two post-secondary educational institutions: Danville Area Community College, a public two-year community college, and Lakeview College of Nursing, a four-year private institution (both located in Danville).

Based on the 2000 census, Vermilion County is part of the Illinois's 15th congressional district; the Illinois Senate districts 52 and 53; and the Illinois House of Representatives districts 104 and 105.

Each township has a supervisor. The township board consists of the supervisor and four members elected at large from the township.

The Vermilion County Board is controlled by Republicans. Larry Baughn (R) of Hoopeston serves as chairman. The Vermilion County Circuit Court is led by Judge Thomas O’Shaugnessy.

United States presidential election results for Vermilion County, Illinois

Year	Republican		Democratic		Third party(ies)
	No.	%	No.	%	No.	%
2020	20,725	65.50%	10,323	32.62%	594	1.88%
2016	19,087	61.93%	10,039	32.58%	1,692	5.49%
2012	16,892	55.57%	12,878	42.36%	630	2.07%
2008	16,054	48.62%	16,246	49.21%	716	2.17%
2004	18,731	55.56%	14,726	43.68%	257	0.76%
2000	15,783	49.17%	15,406	47.99%	911	2.84%
1996	12,015	38.35%	15,525	49.55%	3,789	12.09%
1992	11,703	30.43%	18,383	47.80%	8,375	21.78%
1988	16,943	48.32%	17,918	51.10%	206	0.59%
1984	22,932	57.89%	16,530	41.73%	149	0.38%
1980	22,579	57.07%	14,498	36.64%	2,490	6.29%
1976	19,751	51.24%	18,438	47.83%	357	0.93%
1972	24,863	63.06%	14,413	36.56%	149	0.38%
1968	21,391	49.26%	16,238	37.39%	5,795	13.35%
1964	19,506	44.06%	24,765	55.94%	0	0.00%
1960	26,571	57.34%	19,702	42.51%	69	0.15%
1956	26,534	59.51%	17,991	40.35%	60	0.13%
1952	25,367	57.36%	18,771	42.44%	88	0.20%
1948	18,994	53.29%	16,173	45.37%	479	1.34%
1944	20,794	52.70%	18,387	46.60%	273	0.69%
1940	23,059	49.87%	22,891	49.50%	292	0.63%
1936	18,350	41.56%	25,016	56.65%	790	1.79%
1932	15,643	38.46%	24,032	59.08%	1,002	2.46%
1928	21,616	62.26%	12,728	36.66%	373	1.07%
1924	17,822	54.64%	6,424	19.70%	8,369	25.66%
1920	18,175	61.74%	8,634	29.33%	2,630	8.93%
1916	16,330	50.25%	13,864	42.66%	2,302	7.08%
1912	5,655	32.25%	5,576	31.80%	6,302	35.94%
1908	11,726	60.62%	6,320	32.67%	1,298	6.71%
1904	11,179	66.65%	3,620	21.58%	1,973	11.76%
1900	9,852	59.10%	6,147	36.87%	672	4.03%
1896	8,767	59.14%	5,749	38.78%	309	2.08%
1892	6,892	55.44%	5,001	40.23%	539	4.34%

• Danville Area Community College
• Danville High School
• National Register of Historic Places listings in Vermilion County, Illinois
• Vermilion Regional Airport

• Beckwith, H. W. (1879). History of Vermilion County, together with historic notes on the northwest. Chicago: H. H. Hill and Co.
• Jones, Lottie (1911). History of Vermilion County IL, vol. 1. Chicago: Pioneer Publishing Company.
• Stapp, Katherine; W. I. Bowman (1968). History Under Our Feet: The Story of Vermilion County IL. Danville, Illinois: Interstate Printers and Publishers, Inc.

• Vermilion County official site
• Vermilion County Fact Sheet, Illinois State Archives
• Vermilion County and Danville Public Portal
• Vermilion County Museum
• Vermilion County War Museum
• Vermilion County Forest Preserves
• Cemeteries of Vermilion County Illinois

40°11′N 87°44′W / 40.18°N 87.74°W / 40.18; -87.74