Founding year: Wikidata. First post office: 1850.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 50% of U.S. towns, #212 of 362 in Wisconsin. Its National Register listings hold the grade up; its age pulls it down.
B−
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 2.7 sits near the middle of its state (60% of Wisconsin towns have fewer) while its 1 listings outnumber those of 51% of U.S. towns.
NoteThe founding year comes from Wikidata alone; no second source gives 1853.
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 (±6.3 points).
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 →
What stands out about Janesville’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
Every edition of the U.S. Geological Survey’s map of Janesville. Tap a year, or press play to watch the town change.
1891Janesville 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 Janesville.
Every building
Janesville, building by building, 1884–1915
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 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, 1844 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.
In 1853, according to Wikidata. Janesville’s post office opened in 1850, and the census of 1860 counted 7,703 people here.
How does Janesville rank for history?
Janesville is more historic than 50% of U.S. towns, #212 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?
One place: the John and Eleanor Strunk House (listed 2008).
How old are the homes in Janesville?
13% of Janesville’s homes were built before 1940 (Census estimate, ±6.3 points), against a typical 12% for a Wisconsin town; the median home was built in 1981.
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 (3), Wikidata (9), the National Register of Historic Places (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), 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.
1880
