Each edition grades its towns against each other only.
More historic than 20% of U.S. towns · #631 of 768 in Illinois. What drives it
Most of Cortland Township was built recently: 4% of its homes predate 1940 and the median home dates from 1994. Below: maps from 1937 on and the census since 1880.
Cortland Township dates its founding to 1865 (Wikidata). The census first counted it in 1880.
More historic than 20% of U.S. towns, on its age, its old homes and the National Register.
On its age, its old homes and the National Register, Cortland Township is more historic than 20% of U.S. towns, #631 of 768 in Illinois. Its age holds the grade up; its National Register listings pull it down.
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 Cortland Township’s 0.0 sits below most of its state (28% of Illinois towns have fewer) while its 0 listings outnumber those of 23% of U.S. towns.
Founding year: Wikidata (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 →
Read from the archive, the National Register and the record. The page puts what stands out first.
The first neighbors to add old photos shape how Cortland Township’s history is told.
Lost two-thirds of its people between 1880 and 1910, then grew more than tenfold.
15 censuses, 1880–2020.
U.S. Census Bureau decennial counts, from the census table on Cortland Township’s Wikipedia page.
From Wikipedia’s history of Cortland Township.
A post office called Cortland has been in operation since 1892. The town was named after Cortland, New York.
Text from Wikipedia, licensed CC BY-SA 4.0.
Woven from the archive, old maps, post office records, the National Register and the people born here.
On the mapFirst mapped by the U.S. Geological SurveyWeddings 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 Cortland Township. Tap a year, or press play to watch the town change.
U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of Cortland Township.
Another post office, Ohio Grove, opened and closed inside today’s town.
US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).
Each neighbor’s History grade, on the same three inputs.
In 1865, according to Wikidata. Cortland Township’s post office opened in 1838, and the census of 1880 counted 953 people here.
Cortland Township is more historic than 20% of U.S. towns, #631 of 768 in Illinois. 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.
4% of Cortland Township’s homes were built before 1940 (Census estimate, ±1.9 points), against a typical 11% for an Illinois town; the median home was built in 1994.
What the archives can’t tell you, neighbors can.
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 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.
