More historic than 15% of U.S. towns · #687 of 768 in Illinois. What drives it
Most of Posen was built recently: 8% of its homes predate 1940 and the median home dates from 1965. Below: 1 old photo or paper, maps from 1892 on, and the census since 1910.
On its age, its old homes and the National Register, Posen is more historic than 15% of U.S. towns, #687 of 768 in Illinois. Its share of homes from before 1940 holds the grade up; its age pulls it down.
C−
HistoryA character grade: shown, never part of Posen’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 Posen’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.
How sure. Graded on any two of the three inputs instead, the letter would range from D to C−. The pre-1940 share is a Census survey estimate (±5.2 points).
Founding year: the first census (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 Posen’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
The area that is now Posen was settled by farmers, mainly of Dutch and German origin, in the second half of the 19th century. In 1893 a Chicago-based real estate firm hired 75 agents in the Polish-speaking areas of Germany to sell land to Poles seeking to emigrate to the United States. Over the next few years the village emerged as a place largely inhabited by factory workers, mainly employed at nearby Harvey, who also had room on their lots for gardens. In 1894 the Roman Catholic Archdiocese of Chicago established a mission to serve the Polish residents of Posen, which was elevated to parish status as St. Stanislaus the Martyr in 1898 (the church permanently closed in 2022).
The Posen post office opened in 1910, the earliest record of the town by name (U.S. post office records).
How does Posen rank for history?
Posen is more historic than 15% of U.S. towns, #687 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.
How old are the homes in Posen?
8% of Posen’s homes were built before 1940 (Census estimate, ±5.2 points), against a typical 11% for an Illinois town; the median home was built in 1965.
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 (1), Wikipedia, Wikidata and Wikipedia for famous people, 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.
