Illinois

Iroquois

27,077

2020 population

1840

first census record

census records

About Iroquois

Iroquois, Illinois, first appears in the United States federal census in 1840, when it recorded a population of 1,695. At the most recent census, in 2020, its population stood at 27,077.

Its recorded population peaked at 38,014 in 1900, and has since declined by roughly 29 percent.

On the ground today, 6 places are listed on the National Register of Historic Places.

Population by decade

Census Year	Population	Chart
2020	27,077
2010	29,718
2000	31,334
1990	30,787
1980	32,976
1970	33,532
1960	33,562
1950	32,348
1940	32,496
1930	32,913
1920	34,841
1910	35,543
1900	38,014
1890	35,167
1880	35,451
1870	25,782
1860	12,325
1850	4,149
1840	1,695

Source

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

Historic places in Iroquois

National Register of Historic Places listings in Iroquois, Illinois.

Old Iroquois County Courthouse

Smith, A. Herr and E. E., Public Library

Loda

Prairie Dell Meetinghouse

Iroquois

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Everything a full report reveals about Iroquois County, Illinois

This page charts the census history of Iroquois 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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Illinoishistory ›NRHP historic sites ›Notable people from Illinois›

Frequently asked about Iroquois

When does Iroquois first appear in the US census?

Iroquois, Illinois first appears in the federal census in 1840, with a recorded population of 1,695.

What is the population of Iroquois?

At the most recent federal census (2020), Iroquois had a recorded population of 27,077.

When did Iroquois's population peak?

Iroquois's recorded population peaked at 38,014 in 1900.

How many historic places are in Iroquois?

6 sites are listed on the National Register of Historic Places in Iroquois, Illinois.

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