Founding year: the first Wilmerding post office (Blevins & Helbock, CC0).The full story ↓
History grade
What drives Wilmerding’s History grade
On its age, its old homes and the National Register, Wilmerding is more historic than 73% 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 Wilmerding’s overall grade.
Pennsylvania towns list about as much on the Register as the country (a typical Pennsylvania town has 2.1 per 10,000 residents, the U.S. 2.4), so Wilmerding’s 5.7 sits above most of its state (69% of Pennsylvania 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 A. The pre-1940 share is a Census survey estimate (±7.3 points). The founding year is the first post office, not a stated founding date.
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 Wilmerding’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
George Westinghouse purchased land in the Turtle Creek valley in 1887 and 1888 as a site for his Westinghouse Air Brake Company and related facilities. Westinghouse then sold the land to the East Pittsburgh Improvement Company, incorporated in December 1888, to develop the site, and it began the sale of lots in June 1889.
Wilmerding's most notable historic structure is the Westinghouse Air Brake Company General Office Building (1889–1890, rebuilt 1896), designed by Frederick J. Osterling and now listed on the National Register of Historic Places.
The community was named for Joanna Wilmerding (Bruce) Negley, wife of William B. Negley, who in turn was a local landowner and nephew of Thomas Mellon.
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.
The Wilmerding post office opened in 1889, the earliest record of the town by name (U.S. post office records).
How does Wilmerding rank for history?
Wilmerding is more historic than 73% 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 Wilmerding?
One place: the Westinghouse Air Brake Company General Office Building (listed 1987).
How old are the homes in Wilmerding?
41% of Wilmerding’s homes were built before 1940 (Census estimate, ±7.3 points), against a typical 18% for a Pennsylvania town; the median home was built in 1961.
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 (5), Wikidata (1), the National Register of Historic Places (1), Wikipedia, 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.
1897
1897
1897
1897