Illinois

Union

17,244
2020 population
1820
first census record
21
census records

About Union

Union, Illinois, first appears in the United States federal census in 1820, when it recorded a population of 2,362. At the most recent census, in 2020, its population stood at 17,244.

Its recorded population peaked at 22,610 in 1900, and has since declined by roughly 24 percent.

On the ground today, 7 places are listed on the National Register of Historic Places.

Population by decade

Census YearPopulationChart
202017,244
201017,808
200018,293
199017,619
198017,765
197016,071
196017,645
195020,500
194021,528
193019,883
192020,249
191021,856
190022,610
189021,549
188018,102
187016,518
186011,181
18507,615
18405,524
18303,239
18202,362
Source

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

Historic places in Union

National Register of Historic Places listings in Union, Illinois.

Thompson Brothers Rock Art
Makanda
Ware Mounds and Village Site
Ware
St. Anne's Episcopal Church
Anna
St. Paulus Evangelisch Lutherischen Gemeinde
Jonesboro
Union Lookout
Jonesboro
Campground Church and Cemetery Site
Anna
Stinson Memorial Library
Anna

Other counties in Illinois

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Everything a full report reveals about Union County, Illinois

This page charts the census history of Union 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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Explore Illinois records

Illinoishistory ›NRHP historic sites ›Notable people from Illinois›

Frequently asked about Union

When does Union first appear in the US census?
Union, Illinois first appears in the federal census in 1820, with a recorded population of 2,362.
What is the population of Union?
At the most recent federal census (2020), Union had a recorded population of 17,244.
When did Union's population peak?
Union's recorded population peaked at 22,610 in 1900.
How many historic places are in Union?
7 sites are listed on the National Register of Historic Places in Union, Illinois.
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