California’s post office opened in 1852, and 13% of its homes were built before 1940
How California began
When was California founded?
The California post office opened in 1852, the earliest record of the town by name.
2 famous people were born in California
Writers, athletes, leaders and more, ranked by how widely they’re known.
Places now gone
California’s post office has been open since 1852.
US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).
Questions about California’s history
What year was California founded?
The California post office opened in 1852, the earliest record of the town by name (U.S. post office records).
Memory lane
What the archives can’t tell you, neighbors can.
Where this page comes from
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). How TownRatings grades history →
From Wikidata and Wikipedia for famous people, 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.