The Oak Grove post office opened in 1844, the earliest record of the town by name. Another post office, Minnesota Junction (1861), opened inside today’s town and later closed.
2020 census: 1,028182 years
How historic is Oak Grove?
A−
More historic than 78% of U.S. towns, on its age, its old homes and the National Register.
Founding year: the first Oak Grove post office (Blevins & Helbock, CC0).
History grade
What drives Oak Grove’s History grade
On its age, its old homes and the National Register, Oak Grove is more historic than 78% of U.S. towns. Its share of homes from before 1940 holds the grade up; its National Register listings pull it down.
A−
HistoryA character grade: shown, never part of Oak Grove’s overall grade.
Wisconsin towns list more on the Register than most of the country (a typical Wisconsin town has 3.0 per 10,000 residents, the U.S. 2.4), so Oak Grove’s 0.0 sits below most of its state (28% of Wisconsin 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 B− to A+. The pre-1940 share is a Census survey estimate (±9.0 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 Oak Grove’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
Wikipedia doesn’t have a history of Oak Grove yet. The photos, dates and memories neighbors add here are how it gets written.
Oak Grove (originally called Fairfield) is a town in Dodge County, Wisconsin, United States. The population was 1,028 at the 2020 census. The unincorporated community of Minnesota Junction is located in the town. The unincorporated community of Rolling Prairie is also located partially in the town.
Its first post office opened in 1844. Between the 2010 and 2020 censuses its population fell from 1,080 to 1,028 (-5%).
Intro from Wikipedia. Population: U.S. Census Bureau.
Timeline
Oak Grove, 1844 to 1955
Woven from the archive, old maps, post office records, the National Register and the people born here.
The Oak Grove post office opened in 1844, the earliest record of the town by name (U.S. post office records).
How does Oak Grove rank for history?
Oak Grove is more historic than 78% 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 Oak Grove?
57% of Oak Grove’s homes were built before 1940 (Census estimate, ±9.0 points), against a typical 12% for a Wisconsin town; the median home was built in 1938.
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 (2), U.S. Geological Survey historical maps, 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.
2017
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