New York

Jefferson

116,721
2020 population
1810
first census record
22
census records

About Jefferson

Jefferson, New York, first appears in the United States federal census in 1810, when it recorded a population of 15,140. At the most recent census, in 2020, its population stood at 116,721.

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

On the ground today, 7 documented military engagements have been recorded within the county, among them Kelso Site Iroquoian Violence – Jefferson County, Battle of Lake Ontario (naval) 1756, Battle of Sackett's Harbor, and 150 places are listed on the National Register of Historic Places.

Population by decade

Census YearPopulationChart
2020116,721
2010116,229
2000111,738
1990110,943
198088,151
197088,508
196087,835
195085,521
194084,003
193083,574
192082,250
191080,382
190076,748
189068,806
188066,103
187065,415
186069,825
185068,153
184060,984
183048,493
182032,952
181015,140
Source

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

Battles & engagements in Jefferson

Military engagements that took place in Jefferson, New York.

Kelso Site Iroquoian Violence – Jefferson County
1400
Battle of Lake Ontario (naval) 1756
1756
Battle of Sackett's Harbor
1813
Battle of Lake Ontario — Sackett's Harbor Engagement
1813
Battle of Sackett's Harbor (May 1813)
1813
Second Attack on Sackett's Harbor 1814
1814
Battle of Big Sandy Creek (1814)
1814

Historic places in Jefferson

National Register of Historic Places listings in Jefferson, New York.

District School No. 3
Chaumont
La Farge Land Office
Orleans
La Farge Retainer Houses
Orleans
Union Hotel
Sackets Harbor
Grenadier Island Schoolhouse
Grenadier Island
United Methodist Church
Chaumont
East Charity Shoal Light
Cape Vincent
Madison Barracks
Sackets Harbor
Roxy Hotel
Cape Vincent
Public Square Historic District
Watertown
Watertown Masonic Temple
Watertown
Tracy Farm
Orleans
LeRay Mansion
Black River
LeRay Hotel
Evans Mills
Sackets Harbor Battlefield
Sackets Harbor
Cornwall Brothers' Store
Alexandria Bay
Tibbetts Point Light
Cape Vincent
Cocaigne, Nicholas, House
Cape Vincent
Chevalier, Xavier, House
Cape Vincent
Ressequie Farm
Hounsfield
Stone Mills Union Church
Stone Mills
Longue Vue Island
Alexandria Bay
US Post Office-Carthage
Carthage
St. Paul's Church
Brownville
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Other counties in New York

Explore census history and historic records for more New York counties.

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Everything a full report reveals about Jefferson County, New York

This page charts the census history of Jefferson County, New York. 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 Jefferson

When does Jefferson first appear in the US census?
Jefferson, New York first appears in the federal census in 1810, with a recorded population of 15,140.
What is the population of Jefferson?
At the most recent federal census (2020), Jefferson had a recorded population of 116,721.
Were any battles fought in Jefferson?
7 documented military engagements took place in Jefferson, including Kelso Site Iroquoian Violence – Jefferson County, Battle of Lake Ontario (naval) 1756, Battle of Sackett's Harbor.
How many historic places are in Jefferson?
150 sites are listed on the National Register of Historic Places in Jefferson, New York.
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