Founding year: Wikidata; Wikipedia’s history section gives the same year. First post office: 1858.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 54% of U.S. towns. Its share of homes from before 1940 holds the grade up; its age pulls it down.
B−
HistoryA character grade: shown, never part of Janesville’s overall grade.
Minnesota towns list about as much on the Register as the country (a typical Minnesota town has 2.1 per 10,000 residents, the U.S. 2.4), so Janesville’s 4.2 sits near the middle of its state (60% of Minnesota towns have fewer) while its 1 listings outnumber those of 51% 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 (±4.1 points). Two sources give 1856.
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.
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 city of Janesville was established in 1856. A post office called Janesville has been in operation since 1858. The city was named for Mrs. Jane Sprague, an early settler. Janesville was incorporated in 1870. Janesville contains two properties listed on the National Register of Historic Places, the Hofmann Apiaries established in 1907 and the 1912 Janesville Free Public Library.
Passages that mention Janesville, cut from the printed page as they were published.
Child's history of Waseca County, Minnesota1905 · page 430Read the page →
Read the text
the town of Byron; that $100 be appropriated for repairs on roads and bridges in the town of New Richland; that $75 be appropriated for repairs of roads and bridges in town of Iosco; that $100 be appropriated for repairs of roads and bridges in town of Janesville; that $50 be appropriated to the town of Wilton for replanking the Wilton bridge; that $100 be appropriated for repairs of roads and bridges in town of Blooming Grove, between sections 4 and 9 and on section 23; that $100 be appropriated for repairs of roads and bridges between sections 6 and 7, 19
Text read by machine from the scan; it may contain errors.
Child's history of Waseca County, Minnesota1905 · page 96Read the page →
Read the text
Owatonna road, .$400.00; for the construction of a bridge over the Le Sueur river, at the village of Otisco, $200.00 ; for materials and mechanical labor in constructing a bridge over the outlet to Lake Elysian, in the town of Janesville, on the ]\Iedford and ^Mankato road, .$200.00; for the construction of three bridges in the town of Vivian, on the St. ]\Iary and Vivian road. $100.00; for the construction of a bridge over the inlet to Lake Elysian, town of Iosco, on the iledford and ]\Iankato road, $100.00. These ap-
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, 1856 to 1975
Woven from the archive, old maps, post office records, the National Register and the people born here.
In 1856, according to Wikidata and Wikipedia’s history of the town. Janesville’s post office opened in 1858, and the census of 1880 counted 1,021 people here.
How does Janesville rank for history?
Janesville is more historic than 54% 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.
What is on the National Register in Janesville?
One place: the Janesville Free Public Library (listed 1982).
How old are the homes in Janesville?
17% of Janesville’s homes were built before 1940 (Census estimate, ±4.1 points), against a typical 8.1% for a Minnesota town; the median home was built in 1975.
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 (6), Wikidata (1), 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.
![Owatonna road, .$400.00; for the construction of a bridge over the Le Sueur river, at the village of Otisco, $200.00 ; for materials and mechanical labor in constructing a bridge over the outlet to Lake Elysian, in the town of Janesville, on the ]\Iedford and ^Mankato road, .$200.00; for the constr…](https://images.townratings.com/story/8565/bk-7e290e687cbb9444-l.jpg)
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