The Dahlgren Township post office opened in 1871, the earliest record of the town by name. Wikidata gives 1872. Two smaller post offices, Lovilla (1857) and Delafield (1872), opened inside today’s town and later closed.
First census: 205 in 18802020 census: 1,137155 years
How historic is Dahlgren Township?
C+
More historic than 44% of U.S. towns, on its age, its old homes and the National Register.
Founding year: the first Dahlgren Township post office (Blevins & Helbock, CC0). Wikidata: 1872.The full story ↓
History grade
What drives Dahlgren Township’s History grade
On its age, its old homes and the National Register, Dahlgren Township is more historic than 44% of U.S. towns. Its share of homes from before 1940 holds the grade up; its National Register listings pull it down.
C+
HistoryA character grade: shown, never part of Dahlgren 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 Dahlgren 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.
How sure. Graded on any two of the three inputs instead, the letter would range from C− to B. The pre-1940 share is a Census survey estimate (±8.2 points). The founding year is the first post office, not a stated founding date; Wikidata’s 1872 falls in the same era, so the grade doesn’t depend on which one is used.
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 Dahlgren Township’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
The area around present-day Dahlgren was known in the 1860s as the Shelton Precinct in Hamilton County before townships were formally established. In 1869 surveyors for the St. Louis & South-Eastern Rail Road (predecessor to the Louisville and Nashville Railroad) referred to the future town site as "Little Prairie." Construction of the railroad commenced in 1870 and was completed through the area in late 1871. At that time railroad officials applied to establish a post office in the nascent town which was to be home to the local railroad section boss. After the name "Cottonwood" was rejected by the U. S. postmaster (having already been used in Illinois) the name "Dahlgren" was assigned and the post office commenced operation on December 11, 1871. The village was named for John A. Dahlgren (1809–1870), a U.S. naval officer prominent during the American Civil War. On March 29, 1872, the o…
Every edition of the U.S. Geological Survey’s map of Dahlgren Township. Tap a year, or press play to watch the town change.
1942McLeansboro 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 Dahlgren Township.
Famous people
Famous people close to Dahlgren Township
Nobody well known was born in Dahlgren Township itself, so here are the best known from just nearby.
The Dahlgren Township post office opened in 1871, the earliest record of the town by name (U.S. post office records). Wikidata gives 1872.
How does Dahlgren Township rank for history?
Dahlgren Township is more historic than 44% 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 Dahlgren Township?
23% of Dahlgren Township’s homes were built before 1940 (Census estimate, ±8.2 points), against a typical 11% for an Illinois town; the median home was built in 1968.
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.
