Tredyffrin Township dates to 1707, and 14 of its places are on the National Register
More historic than 84% of U.S. towns · #274 of 1,035 in Pennsylvania. What drives it
Most of Tredyffrin Township was built recently: 8% of its homes predate 1940 and the median home dates from 1974. Below: maps from 1894 on and the census since 1930.
Founding year: Wikidata; Wikipedia’s history section gives the same year. First post office: 1826.The full story ↓
History grade
What drives Tredyffrin Township’s History grade
On its age, its old homes and the National Register, Tredyffrin Township is more historic than 84% of U.S. towns, #274 of 1,035 in Pennsylvania. Its age holds the grade up; its share of homes from before 1940 pulls it down.
A−
HistoryA character grade: shown, never part of Tredyffrin Township’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 Tredyffrin Township’s 6.6 sits above most of its state (71% of Pennsylvania towns have fewer) while its 21 historic buildings outnumber those of 80% of U.S. towns.
How sure. Graded on any two of the three inputs instead, the letter would range from B to A+. The pre-1940 share (±2.5 points) is firm at this size. Two sources give 1707.
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 Tredyffrin Township’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
Chester Valley Post Officepost officeHobson Airportairport
13cemeteries and burying grounds inside Tredyffrin Township
Diamond Rock MennonistGreat Valley Baptist ChurchGreat Valley PresbyterianMount PleasantMount Zion African Methodist Episcopal ChurchOld EagleOur Lady of the AssumptionRick's MemorialSaint Luke Memorial GardenSaint MonicaSalemValley Forge Military Academy and CollegeValley Friends Meeting
US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).
Help out
Start Tredyffrin Township’s collection
The first neighbors to add old photos shape how Tredyffrin Township’s history is told.
Decades since 1900 with photos
00s10s20s30s40s50s60s70s80s90s
0 of 10 decades. The empty ones are waiting for someone’s album.
On March 13, 1684, William Penn decided to set aside a portion of what was then the Province of Pennsylvania for settlements for Welsh immigrants. This area, known as the "Welsh Tract", was surveyed in 1684 and included several modern-day townships, including Tredyffrin. Although the Welsh Tract was originally meant to be a self-ruling municipality, it was divided between Chester County and Philadelphia when that county was created in 1685, and the Welsh subsequently submitted to the authority of Chester County. In 1707, Tredyffrin was incorporated as a township. This name comes from the Welsh tre(f), which means "town", joined to dyffryn, which means "wide, cultivated valley". Tredyffrin was quick to develop into a thriving township. In 1710, the first mill in Tredyffrin was started by Thomas Jerman on what is now North Valley Road. Swedesford Road, one of the first roads in…
Passages that mention Tredyffrin Township, cut from the printed page as they were published.
The history of the Old Eagle School, Tredyffrin, in Chester County, Pennsylvania1909 · page 174Read the page →
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All that certain lot or piece of ground, with the building-s and improvements thereon erected, situate in Tredyffrin Township, Chester County, Penna., on the public road leading from Strafford Station, Penna. Railroad, Northwardly toward Port Kennedy, beginning at a point in the Eastwardly side of said road at or near the intersection of the lines of land of Daniel S. Newhall and Dr. T. G. Morton ; thence by land now
Text read by machine from the scan; it may contain errors.
The history of the Old Eagle School, Tredyffrin, in Chester County, Pennsylvania1909 · page 177Read the page →
Read the text
ment of the Trust declared by the Court of Common Pleas of Chester County, Pennsylvania, to exist in reference to the Old Eagle School property at Strafford Station, Pennsylvania Railroad, in Tredyffrin Township, for the general use and good of the neighborhood for religious, educational and burial purposes, do hereby subscribe the amount set opposite to our names towards defraying the cost of the necessary repairs and improvements of said property and expenses,
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
Tredyffrin Township, 1707 to 1993
Woven from the archive, old maps, post office records, the National Register and the people born here.
Every edition of the U.S. Geological Survey’s map of Tredyffrin Township. Tap a year, or press play to watch the town change.
1894Norristown 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 Tredyffrin Township.
People over time
Tredyffrin Township, census by census
Grew from 5,458 people in 1930 to 31,927 in 2020, 5 times over.
10 censuses, 1930–2020.
U.S. Census Bureau decennial counts, from the census table on Tredyffrin Township’s Wikipedia page.
Famous people
4 famous people were born in Tredyffrin Township
Writers, athletes, leaders and more, ranked by how widely they’re known.
In 1707, according to Wikidata and Wikipedia’s history of the town. Tredyffrin Township’s post office opened in 1826, and the census of 1930 counted 5,458 people here.
How does Tredyffrin Township rank for history?
Tredyffrin Township is more historic than 84% of U.S. towns, #274 of 1,035 in Pennsylvania. 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 Tredyffrin Township?
14 listings: 13 buildings, among them the Wharton Esherick Studio (a National Historic Landmark since 1993) and the Cressbrook Farm (listed 1972, the first), and 1 structure. 21 historic buildings in all.
How old are the homes in Tredyffrin Township?
8% of Tredyffrin Township’s homes were built before 1940 (Census estimate, ±2.5 points), against a typical 18% for a Pennsylvania town; the median home was built in 1974.
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 Wikidata (4), the National Register of Historic Places (14), 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 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.
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