Illinois

Williamson

67,153

2020 population

1840

first census record

census records

About Williamson

Williamson, Illinois, first appears in the United States federal census in 1840, when it recorded a population of 4,457. At the most recent census, in 2020, its population stood at 67,153.

The county's recorded population has risen across the decades to its highest level in 2020.

On the ground today, 43 places are listed on the National Register of Historic Places.

Population by decade

Census Year	Population	Chart
2020	67,153
2010	66,357
2000	61,296
1990	57,733
1980	56,538
1970	49,021
1960	46,117
1950	48,621
1940	51,424
1930	53,880
1920	61,092
1910	45,098
1900	27,796
1890	22,226
1880	19,324
1870	17,329
1860	12,205
1850	7,216
1840	4,457

Source

Population data from the United States decennial census, U.S. Census Bureau (public domain).

Historic places in Williamson

National Register of Historic Places listings in Williamson, Illinois.

Williamson County Jail

Stotlar, Ed. M., House

Marion

Marion Veterans Administration Hospital Historic District

Marion

Browse all Illinoishistoric sites ›

Other counties in Illinois

Explore census history and historic records for more Illinois counties.

Woodford Adams Alexander Bond Boone Brown Bureau Calhoun Carroll Cass Champaign Christian Clark Clay Clinton Coles Cook Crawford Cumberland De Witt

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Everything a full report reveals about Williamson County, Illinois

This page charts the census history of Williamson County, Illinois. A full Aubrey report for an address here pulls together everything the historical record holds about the ground, from the earliest settlement to the twentieth century:

Overview

An interactive map of the location with historic sites, battles and Native heritage plotted, and its full story era by era.

The Land

The historic sites and place names around the location, and how this land was settled and used.

Geology

The bedrock beneath the site, its age and rock type, reaching back millions of years.

LiDAR Terrain

Laser-scanned terrain that reveals earthworks and old features hidden in the landscape.

Conflict & War

The battles, raids and skirmishes fought near here, across every era of American conflict.

The Civil War

The Civil War on this ground, 1861 to 1865: who held it, and the battles, camps and regiments nearby.

The Soldiers

The men who marched from here in the Civil War, named and traced where the record allows.

Native Heritage

The Native nations who held this land, mapped across time from before European contact to today.

Settlement

Who claimed and held this ground, from Indigenous homelands through the colonial powers to the United States.

The Community

How the town grew, who came, and what kind of place it became, traced through the census record.

Rivers & Rail

The rivers, canals and railroads that connected this place between 1830 and 1911.

Notable People

The people born, buried or genuinely tied to this exact place, with their stories.

Historical Maps

Historic maps of the location layered over how it looks today.

Finds & Access

Museum objects tied to the area, and the laws on searching, collecting and access here.

Literature

The old books, county histories and archives that mention this place, quoted with their sources.

Spotlight

A deep dive into the most remarkable, lesser-known history of the place, traced back to the record.

Points of Interest

The most significant historic sites and landmarks near the location, and why they matter.

Timeline

The whole story of the location told era by era, from first peoples to the present day.

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Frequently asked about Williamson

When does Williamson first appear in the US census?

Williamson, Illinois first appears in the federal census in 1840, with a recorded population of 4,457.

What is the population of Williamson?

At the most recent federal census (2020), Williamson had a recorded population of 67,153.

How many historic places are in Williamson?

43 sites are listed on the National Register of Historic Places in Williamson, Illinois.

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