On its age, its old homes and the National Register, Heidelberg is more historic than 38% of U.S. towns. Its share of homes from before 1940 holds the grade up; its age pulls it down.
C+
HistoryA character grade: shown, never part of Heidelberg’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 Heidelberg’s 0.0 sits below most of its state (25% of Pennsylvania towns have fewer) while its 0 listings outnumber those of 23% of U.S. towns.
How sure. Graded on any two of the three inputs instead, the letter would range from D to B. The pre-1940 share is a Census survey estimate (±13.3 points). Two sources give 1903.
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 Heidelberg’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
Peaked at 2,250 in 1950; 1,288 people lived here in 2020.
12 censuses, 1910–2020.
U.S. Census Bureau decennial counts, from the census table on Heidelberg’s Wikipedia page.
On the map
Heidelberg on the map, 1904 to 1993
Every edition of the U.S. Geological Survey’s map of Heidelberg. Tap a year, or press play to watch the town change.
1904Carnegie 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 Heidelberg.
The story so far
Heidelberg, in brief
Wikipedia doesn’t have a history of Heidelberg yet. The photos, dates and memories neighbors add here are how it gets written.
Heidelberg is a borough located southwest of Pittsburgh in Allegheny County, Pennsylvania, United States. The population was 1,288 at the 2020 census. The borough was named after Heidelberg in Germany, the native home of a large share of the early settlers.
Heidelberg was established in 1903. Between the 2010 and 2020 censuses its population grew from 1,244 to 1,288 (+4%).
Intro from Wikipedia. Population: U.S. Census Bureau.
Timeline
Heidelberg, 1894 to 1950
Woven from the archive, old maps, post office records, the National Register and the people born here.
In 1903, according to Wikidata. the census of 1910 counted 1,848 people here.
How does Heidelberg rank for history?
Heidelberg is more historic than 38% 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.
How old are the homes in Heidelberg?
38% of Heidelberg’s homes were built before 1940 (Census estimate, ±13.3 points), against a typical 18% for a Pennsylvania town; the median home was built in 1948.
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 (3), Wikidata and Wikipedia for famous people, U.S. Geological Survey historical maps, U.S. Census counts (via Wikipedia) 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.
2014
2014
2007