Newcastle’s post office opened in 1864, and 11% of its homes were built before 1940
More historic than 54% of U.S. towns. What drives it
Its Register listing is the Newcastle Portuguese Hall.
How Newcastle began
When was Newcastle founded?
The Newcastle post office opened in 1864, the earliest record of the town by name.
How historic is Newcastle?
More historic than 54% of U.S. towns, on its age, its old homes and the National Register.
What drives Newcastle’s History grade
On its age, its old homes and the National Register, Newcastle is more historic than 54% of U.S. towns. Its National Register listings hold the grade up; its age pulls it down.
Few California towns list much on the Register (a typical California town has 0.0 per 10,000 residents, the U.S. 2.4), so Newcastle’s 6.3 sits above most of its state (89% of California towns have fewer) while its 1 listings outnumber those of 51% of U.S. towns.
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 →
1 historic place in Newcastle
The country’s official list of buildings and places worth saving.
National Park Service, National Register of Historic Places. Photos from Wikimedia Commons, credited on each place’s page.
Questions about Newcastle’s history
What year was Newcastle founded?
The Newcastle post office opened in 1864, the earliest record of the town by name (U.S. post office records).
How does Newcastle rank for history?
Newcastle 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 Newcastle?
One place: the Newcastle Portuguese Hall (listed 1982).
How old are the homes in Newcastle?
11% of Newcastle’s homes were built before 1940 (Census estimate, ±6.6 points), against a typical 3.4% for a California town; the median home was built in 1978.
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).
From the National Register of Historic Places (1), 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.