New Jersey

Mercer

387,340
2020 population
1840
first census record
19
census records

About Mercer

Mercer, New Jersey, first appears in the United States federal census in 1840, when it recorded a population of 21,502. At the most recent census, in 2020, its population stood at 387,340.

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

On the ground today, 11 documented military engagements have been recorded within the county, among them Battle of Trenton Dec 26 1776, First Battle of Trenton, Battle of Trenton (First), and 117 places are listed on the National Register of Historic Places.

Population by decade

Census YearPopulationChart
2020387,340
2010366,513
2000350,761
1990325,824
1980307,863
1970303,968
1960266,392
1950229,781
1940197,318
1930187,143
1920159,881
1910125,657
190095,365
189079,978
188058,061
187046,386
186037,419
185027,992
184021,502
Source

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

Battles & engagements in Mercer

Military engagements that took place in Mercer, New Jersey.

Battle of Trenton Dec 26 1776
1776
First Battle of Trenton
1776
Battle of Trenton (First)
1776
Skirmish at Maidenhead
1777
Battle of Assunpink Creek (Second Trenton)
1777
Second Battle of Trenton
1777
Battle of Assunpink Creek / Second Trenton Jan 2 1777
1777
Battle of Princeton
1777
Second Battle of Trenton Jan 2 1777
1777
Battle of Princeton Jan 3 1777
1777
New Jersey Copperhead Suppression
1863

Historic places in Mercer

National Register of Historic Places listings in Mercer, New Jersey.

Bellevue Avenue Colored School
Trenton
Nassau Hall, Princeton University
Princeton
President's House
Princeton
Trenton Friends Meeting House
Trenton
Mercer Street Friends Center
Trenton
Roebling's, John A., Sons Company, Trenton N.J., Block 3
Trenton
Douglass House
Trenton
Old Eagle Tavern
Trenton
Clay, Henry and Bock and Company Cigar Factory
Trenton
Abbott Farm Archeological Site
Trenton
Drake Farmstead-Brookdale Farm (Additional Documentation)
Hopewell Township
Cleveland, Grover, Home
Princeton
Drumthwacket
Princeton
East Trenton Public Library
Trenton
Hog Island Cranes
Trenton
Hunt Farmstead
Rosedale
Old Ryan Farm
Trenton
Penns Neck Baptist Church
Penns Neck
Morven
Princeton
Mill Hill Historic District
Trenton
Lawrenceville School
Lawrenceville
Mountain Avenue Historic District
Princeton
Sloan, Samuel, House
Hightstown
Trenton and Mercer County War Memorial-Soldiers' and Sailors' Memorial Building
Trenton
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Other counties in New Jersey

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Everything a full report reveals about Mercer County, New Jersey

This page charts the census history of Mercer County, New Jersey. 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 Mercer

When does Mercer first appear in the US census?
Mercer, New Jersey first appears in the federal census in 1840, with a recorded population of 21,502.
What is the population of Mercer?
At the most recent federal census (2020), Mercer had a recorded population of 387,340.
Were any battles fought in Mercer?
11 documented military engagements took place in Mercer, including Battle of Trenton Dec 26 1776, First Battle of Trenton, Battle of Trenton (First).
How many historic places are in Mercer?
117 sites are listed on the National Register of Historic Places in Mercer, New Jersey.
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