From Mount Carroll Township’s archive · credits on each photo
Quick answers
How Mount Carroll Township began
When was Mount Carroll Township founded?
1845
The Mount Carroll Township post office opened in 1845, the earliest record of the town by name. Another post office, Wacker (1894), opened inside today’s town and later closed.
First census: 462 in 18502020 census: 1,963181 years
How historic is Mount Carroll Township?
A+
More historic than 98% of U.S. towns, on its age, its old homes and the National Register.
Founding year: the first Mount Carroll Township post office (Blevins & Helbock, CC0).The full story ↓
History grade
What drives Mount Carroll Township’s History grade
On its age, its old homes and the National Register, Mount Carroll Township is more historic than 98% of U.S. towns. All 3 inputs are above most U.S. towns; its National Register listings ranks highest and its age lowest.
A+
HistoryA character grade: shown, never part of Mount Carroll Township’s overall grade.
Few Illinois towns list much on the Register (a typical Illinois town has 0.5 per 10,000 residents, the U.S. 2.4), so Mount Carroll Township’s 929 sits above most of its state (99% of Illinois towns have fewer) while its 179 historic buildings outnumber those of 93% of U.S. towns.
How sure. Graded on any two of the three inputs instead, the letter would range from A to A+. The pre-1940 share is a Census survey estimate (±6.1 points). The founding year is the first post office, not a stated founding date.
Founding year: the first post office (other dates in Quick answers). Homes: Census ACS 2020–24. National Register: National Park Service, May 2026 list; each listing counted once (boundary changes and added documentation belong to their listing), and a historic district counts its contributing buildings. How TownRatings grades history →
What stands out about Mount Carroll Township’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
Peaked at 2,143 in 1970; 1,479 people lived here in 2020.
17 censuses, 1850–2020.
U.S. Census Bureau decennial counts, from the census table on Mount Carroll Township’s Wikipedia page.
Places that used to be
Lost post offices, old corners, places now gone and burying grounds
Another post office, Wacker, opened and closed inside today’s town.
Hamlets and corners on the map
BurkeCenter HillHickory GroveWacker
Gone or out of use
Carroll County FarmlocaleFairground SchoolschoolFerrin SchoolschoolHickory Grove SchoolschoolLawrence QuarrymineLocust Grove SchoolschoolMount Carroll QuarryminePleasant Hill SchoolschoolPlum Grove SchoolschoolPreston Prairie Schoolschool
2cemeteries and burying grounds inside Mount Carroll Township
Center HillWacker
US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).
The story
How Mount Carroll Township came to be
From Wikipedia’s history of Mount Carroll Township.
Mount Carroll began as a mill town around 1841. In 1843, a referendum moved the county seat from nearby Savanna to Mount Carroll. The town was incorporated in 1855 and became a city in 1867; the first mayor was Nathaniel Halderman, a prominent local businessman and co-founder of the mill.
Shimer College was established in Mt. Carroll in 1853, but mounting debts forced a move to Waukegan in 1979 and subsequently to Chicago in 2006. The campus now is home to several organizations, most notably the Campbell Center for Historic Preservation Studies.
Nothing in the archives for these yearsWeddings on Main Street, storms, parades, school pictures, the old store. If it’s in your family album, it belongs here.
Nothing in the archives for these yearsWeddings on Main Street, storms, parades, school pictures, the old store. If it’s in your family album, it belongs here.
Every edition of the U.S. Geological Survey’s map of Mount Carroll Township. Tap a year, or press play to watch the town change.
1952Savanna sheet · 1:62,500
U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of Mount Carroll Township.
Then & now
Stand where they stood
No then-and-now pairs yet. Take a photo from the same spot as an old one and they appear here side by side.
Retake this viewFrances Shimer Academy ad 1906, 1906
Find the spot, match the angle, and add your photo. It becomes the first then-and-now pair on Mount Carroll Township’s page.
The Mount Carroll Township post office opened in 1845, the earliest record of the town by name (U.S. post office records).
How does Mount Carroll Township rank for history?
Mount Carroll Township is more historic than 98% of U.S. towns. The History grade combines the town’s founding era, the share of homes built before 1940 and its National Register listings. It’s a character grade, so it isn’t part of the overall grade. How it works.
How old are the homes in Mount Carroll Township?
38% of Mount Carroll Township’s homes were built before 1940 (Census estimate, ±6.1 points), against a typical 11% for an Illinois town; the median home was built in 1958.
Founding dates: Wikidata, Wikipedia, the U.S. post office records of Blevins & Helbock (CC0) and the Census. Homes by year built: Census ACS 2020–24. National Register of Historic Places: National Park Service (list of May 22, 2026). Old photos, postcards and papers: Wikimedia Commons, the Library of Congress and other public archives, credited on each item’s page. Maps: U.S. Geological Survey historical topographic maps (via Esri) and Sanborn fire-insurance maps (Library of Congress). History text and census tables: Wikipedia (CC BY-SA 4.0). Places that used to be: USGS Geographic Names Information System (2021).
From Wikimedia Commons (10), the Library of Congress (1), Wikidata (4), Wikipedia, U.S. Geological Survey historical maps, U.S. Census counts (via Wikipedia), the US Post Offices dataset (Blevins & Helbock) and the USGS Geographic Names Information System. Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
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