Ohio

Allen

102,206
2020 population
1830
first census record
20
census records

About Allen

Allen, Ohio, first appears in the United States federal census in 1830, when it recorded a population of 578. At the most recent census, in 2020, its population stood at 102,206.

Its recorded population peaked at 112,241 in 1980, and has since declined by roughly 9 percent.

On the ground today, one documented military engagement has been recorded within the county, among them Treaty of Greenville – Wyandot Resistance 1795, and 31 places are listed on the National Register of Historic Places.

Population by decade

Census YearPopulationChart
2020102,206
2010106,331
2000108,473
1990109,755
1980112,241
1970111,144
1960103,691
195088,183
194073,303
193069,419
192068,223
191056,580
190047,976
189040,644
188031,314
187023,623
186019,185
185012,109
18409,079
1830578
Source

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

Battles & engagements in Allen

Military engagements that took place in Allen, Ohio.

Treaty of Greenville – Wyandot Resistance 1795
1795

Historic places in Allen

National Register of Historic Places listings in Allen, Ohio.

Miami And Erie Canal, Deep Cut
Spencerville
Barr Hotel
Lima
Allen County Courthouse
Lima
Hotel Argonne
Lima
Lima Pennsylvania Railroad Passenger Depot
Lima
Adgate Block
Lima
Lima Memorial Hall
Lima
Union Block
Lima
First National Bank and Trust Building
Lima
Dorsey Building
Lima
Renz Block
Lima
Ohio Theatre
Lima
Klaus Block
Lima
Martin Block and Kibby Block
Lima
Linneman Building
Lima
Marks-Family House
Delphos
Neely-Sieber House
Lima
Metropolitan Block
Lima
St. John Catholic Church
Delphos
Cahill, Beck and R. C., Buildings
Lima
U.S. Post Office
Lima
Elks Lodge
Lima
Neal Clothing
Lima
Armory-Latisona Building
Lima
Browse all Ohiohistoric sites ›

Other counties in Ohio

Explore census history and historic records for more Ohio counties.

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Everything a full report reveals about Allen County, Ohio

This page charts the census history of Allen County, Ohio. 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 Allen

When does Allen first appear in the US census?
Allen, Ohio first appears in the federal census in 1830, with a recorded population of 578.
What is the population of Allen?
At the most recent federal census (2020), Allen had a recorded population of 102,206.
When did Allen's population peak?
Allen's recorded population peaked at 112,241 in 1980.
Were any battles fought in Allen?
1 documented military engagement took place in Allen, including Treaty of Greenville – Wyandot Resistance 1795.
How many historic places are in Allen?
31 sites are listed on the National Register of Historic Places in Allen, Ohio.
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