Connecticut

Middlesex

164,245
2020 population
1790
first census record
24
census records

About Middlesex

Middlesex, Connecticut, first appears in the United States federal census in 1790, when it recorded a population of 18,855. At the most recent census, in 2020, its population stood at 164,245.

Its recorded population peaked at 165,676 in 2010, and has since declined by roughly 1 percent.

On the ground today, 9 documented military engagements have been recorded within the county, among them Fort Saybrook Skirmishes, Pequot War Raids on Connecticut 1636-1637, Battle at Saybrook Fort (Pequot War 1636), and 127 places are listed on the National Register of Historic Places.

Population by decade

Census YearPopulationChart
2020164,245
2010165,676
2000155,071
1990143,196
1980129,017
1970114,816
196088,865
195067,332
194055,999
193051,388
192047,550
191045,637
190041,760
189039,524
188035,589
187036,099
186030,859
185027,216
184024,879
183024,844
182022,405
181020,723
180019,847
179018,855
Source

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

Battles & engagements in Middlesex

Military engagements that took place in Middlesex, Connecticut.

Fort Saybrook Skirmishes
1636
Pequot War Raids on Connecticut 1636-1637
1636
Battle at Saybrook Fort (Pequot War 1636)
1636
Siege of Saybrook Fort 1636-1637
1637
Siege of Fort Saybrook
1637
Battle of Haddam CT 1676
1676
Skirmish at Pettipauge CT (Essex)
1814
British Raid on Pettipaug Point, Connecticut
1814
British Raid on Pettipaug Point CT (Apr 8 1814)
1814

Historic places in Middlesex

National Register of Historic Places listings in Middlesex, Connecticut.

Xi Chapter, Psi Upsilon Fraternity
Middletown
Main Street Historic District
Durham
Fenwick Historic District
Fenwick
Wadsworth Estate Historic District
Middletown
Whittlesey, John, Jr., House
Old Saybrook
Centerbrook Congregational Church
Essex
Millington Green Historic District
East Haddam
Stevens, William, House
Clinton
Washington Street Historic District
Middletown
Bushnell-Dickinson House
Old Saybrook
Alsop, Richard IV, House
Middletown
Lyman, David, II, House
Middlefield
Warner House
East Haddam
Rapallo Viaduct
East Hampton
Westbrook Town Center Historic District
Westbrook
Middletown Alms House
Middletown
Ward, William, Jr., House
Middlefield
Clinton Village Historic District
Clinton
Hazelton, James, House
Haddam
Church of the Holy Trinity and Rectory
Middletown
Day, Amasa, House
Moodus
DORIS (Sailing yacht)
Deep River
Hadlyme North Historic District
East Haddam
Belltown Historic District
East Hampton
Browse all Connecticuthistoric sites ›

Other counties in Connecticut

Explore census history and historic records for more Connecticut counties.

LitchfieldNew HavenNew LondonTollandWindhamFairfieldHartford
Unlimited access

Everything a full report reveals about Middlesex County, Connecticut

This page charts the census history of Middlesex County, Connecticut. 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.
First month just $5.99, then $11.99 a month. Unlimited locations, cancel anytime.

Every location is different. Not every section appears for every place, only what the historical record actually holds turns up in a report.

Start your Middlesex County, Connecticut report
Or see a real report first

Explore Connecticut records

Connecticuthistory ›NRHP historic sites ›Notable people from Connecticut›

Frequently asked about Middlesex

When does Middlesex first appear in the US census?
Middlesex, Connecticut first appears in the federal census in 1790, with a recorded population of 18,855.
What is the population of Middlesex?
At the most recent federal census (2020), Middlesex had a recorded population of 164,245.
When did Middlesex's population peak?
Middlesex's recorded population peaked at 165,676 in 2010.
Were any battles fought in Middlesex?
9 documented military engagements took place in Middlesex, including Fort Saybrook Skirmishes, Pequot War Raids on Connecticut 1636-1637, Battle at Saybrook Fort (Pequot War 1636).
How many historic places are in Middlesex?
127 sites are listed on the National Register of Historic Places in Middlesex, Connecticut.
Aubrey Research

Research the history of any US location

Aubrey searches federal archives, archaeological records, historic registers, and primary sources to build a full historical report for any address or place in the United States.

Research your locationView a free sample report