Janesville’s post office opened in 1837, and 14% of its homes were built before 1940
More historic than 90% of U.S. towns · #39 of 362 in Wisconsin. What drives it
36 places in town are on the National Register, among them ten historic districts with 2,424 buildings between them. Below: 9 old photos and papers, maps from 1884 on, and the census since 1860.
Founding year: the first Janesville post office (Blevins & Helbock, CC0). Wikidata: 1853.The full story ↓
History grade
What drives Janesville’s History grade
On its age, its old homes and the National Register, Janesville is more historic than 90% of U.S. towns, #39 of 362 in Wisconsin. All 3 inputs are above most U.S. towns; its National Register listings ranks highest and its share of homes from before 1940 lowest.
A
HistoryA character grade: shown, never part of Janesville’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 Janesville’s 372 sits above most of its state (99% of Wisconsin towns have fewer) while its 2,454 historic buildings outnumber those of 99% 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 (±1.3 points) is firm at this size. The founding year is the first post office, not a stated founding date; Wikidata gives 1853.
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 Janesville’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
The area that became Janesville was the site of a Ho-Chunk village named Įnį poroporo (Round Rock) up to the time of Euro-American settlement. In the 1825 Treaty of Prairie du Chien, the United States recognized the portion of the present city that lies west of the Rock River as Ho-Chunk territory, while the area east of the river was recognized as Potawatomi land. Following the Indian Removal Act of 1830 and the Black Hawk War of 1832, both nations were forced to surrender this land to the United States.
Passages that mention Janesville, cut from the printed page as they were published.
The history of Rock County, Wisconsin1879 · page 526Read the page →
Read the text
and was the first surveyed village (or city) in the county. ' Wisconsin City ' was surveyed by Inman, Breese and Shepherd, in 1836 ; ' City of Koshkonong,' in the summer of the same year, by Kenzie, Hunter and Booby; ' Monterey,' by Ira Miltimore, in 1850. By an act of the Legislature of Wisconsin, approved March 19, 1853, the city of Janesville was incorporated, and, by its charter, Sections 1 and 2 of the town of Rock were brought within its limits. Consequently, ' Monterey ' and ' Rockport ' are now a part of the territory belonging to the city of Janesville. With Sections 1 and 2, there also passed from the town many of the localities where the scenes before described transpired."
Text read by machine from the scan; it may contain errors.
The history of Rock County, Wisconsin1879 · page 512Read the page →
Read the text
The foregoing were all the officers of the town of Janesville so long as its territory included thirty-six sections of land, or previous to any portion of it being included within the chartered limits of the city of Janesville.
Text read by machine from the scan; it may contain errors.
Scans and text from the Internet Archive. Books published in 1930 or earlier, which are in the public domain.
Timeline
Janesville, 1837 to 1981
Woven from the archive, old maps, post office records, the National Register and the people born 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.
Fire insurance maps drew every building, what it was made of and what it was used for, so insurers could price the risk of fire. Pick a year, then a sheet.
The Janesville post office opened in 1837, the earliest record of the town by name (U.S. post office records). Wikidata gives 1853.
How does Janesville rank for history?
Janesville is more historic than 90% of U.S. towns, #39 of 362 in Wisconsin. 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.
What is on the National Register in Janesville?
36 listings: 23 buildings, among them the Tallman House (listed 1970, the first), and 13 historic districts with 2,424 contributing buildings. 2,454 historic buildings in all.
How old are the homes in Janesville?
14% of Janesville’s homes were built before 1940 (Census estimate, ±1.3 points), against a typical 12% for a Wisconsin town; the median home was built in 1972.
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 the Library of Congress (9), Wikidata (9), the National Register of Historic Places (36), 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), the USGS Geographic Names Information System, Sanborn fire insurance maps (Library of Congress) and old county and town histories (Internet Archive). Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
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