Guest, Sign inJoin

Post to Monongahela

We’ll email a one-tap link to publish your post. No password, and nothing is public until you click it.
Already a member? Sign in
A+History
History · Monongahela

Monongahela dates to 1769, and 52% of its homes were built before 1940

Among the most historic 1% of U.S. towns · #41 of 1,035 in Pennsylvania. What drives it

4 places in town are on the National Register, among them the Edward G. Acheson House, a National Historic Landmark. 4 places in town are on the National Register, among them the Edward G. Acheson House, a National Historic Landmark. Below: 8 old photos and papers, maps from 1902 on, and the census since 1840.

1769founded
4on the National Register
52%homes built before 1940
8old photos & papers
18famous people
Add an old photoShare a memory
From Monongahela’s archive · credits on each photo
Quick answers

How Monongahela began

When was Monongahela founded?

1769

Monongahela dates its founding to 1769 (Wikipedia’s history). The census first counted it in 1840.

First census: 752 in 18402020 census: 4,159257 years

How historic is Monongahela?

A+

Among the most historic 1% of U.S. towns, on its age, its old homes and the National Register.

What drives the grade ↓
Founding year: Wikipedia. First post office: 1837.The full story ↓
History grade

What drives Monongahela’s History grade

On its age, its old homes and the National Register, Monongahela is among the most historic 1% of U.S. towns, #41 of 1,035 in Pennsylvania. All 3 inputs are above most U.S. towns; its share of homes from before 1940 ranks highest and its National Register listings lowest.

A+
HistoryA character grade: shown, never part of Monongahela’s overall grade.
Founding era1769, from Wikipedia: founded before 1776, an older era than 96% of U.S. townsA+Homes built before 194052.2% of homes (±7.7) · typical PA town 17.7% · U.S. 8.4%A+National Register4 listings, 10 historic buildings, 24.3 per 10,000 residents · typical PA town 2.1 · U.S. 2.4A−
All U.S. towns we grade (21,289)Among the top 1%
NewerOlder
Pennsylvania towns of 2,500+ (1,035)Ahead of 96%

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 Monongahela’s 24.3 sits above most of its state (83% of Pennsylvania towns have fewer) while its 10 historic buildings outnumber those of 76% of U.S. towns.

How sure. Graded on any two of the three inputs instead, the letter would still be A+. The pre-1940 share is a Census survey estimate (±7.7 points). Two sources give 1769.

Founding year: Wikipedia (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 Monongahela’s past

Read from the archive, the National Register and the record. The page puts what stands out first.

Old housesHalf of Monongahela’s homes were built before 1938.On the map since 19027 editions of the USGS map, 1902 to 1993. Watch Monongahela change.Boom and bustPeaked at 8,922 in 1950; 4,159 people lived here in 2020.Lost villages2 post offices opened and closed inside today’s Monongahela, and 2 old place names are still on the map.
★ What stands out · The story

How Monongahela came to be

From Wikipedia’s history of Monongahela.

Read it all →

Monongahela was founded in 1769 on a tract of land near the confluence of Pigeon Creek and the Monongahela River. It is the oldest settlement in the Monongahela River Valley and most likely the oldest in Washington County. The word Monongahela is Native American in origin, meaning "falling banks". The Monongahela tribe was also indigenous to the area prior to the settlement of the city.

Text from Wikipedia, licensed CC BY-SA 4.0.

On the map

Monongahela on the map, 1902 to 1993

Every edition of the U.S. Geological Survey’s map of Monongahela. Tap a year, or press play to watch the town change.

Monongahela on the 1902 USGS mapMonongahela on the 1931 USGS mapMonongahela on the 1940 USGS mapMonongahela on the 1954 USGS mapMonongahela on the 1969 USGS mapMonongahela on the 1979 USGS mapMonongahela on the 1993 USGS map1902Brownsville 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 Monongahela.

People over time

Monongahela, census by census

02,0004,0006,0008,0001850190019502000Peak: 8,922

Peaked at 8,922 in 1950; 4,159 people lived here in 2020.

19 censuses, 1840–2020.

U.S. Census Bureau decennial counts, from the census table on Monongahela’s Wikipedia page.

Timeline

Monongahela, 1769 to 1976

Woven from the archive, old maps, post office records, the National Register and the people born here.

  1. 18th century
  2. 1769
    FoundingMonongahela is established
  3. 19th century
  4. 1815In the archiveAmerican Telegraph 7-5-1815
  5. 1837Post officeThe Monongahela City post office opens
  6. 1863BuiltMonongahela Cemetery is built
  7. 1880In the archive1940 Census Enumeration District Maps - Pennsylvania - Washington County - Monongahela - …
  8. 1893Post officeThe Monongahela City post office closes
  9. 1893Post officeThe Monongahela post office opens
  10. 1898Post officeThe Hazzard post office opens
  11. 20th century
  12. 1902In the archiveMonongahela City, Pennsylvania, 1902
  13. 1902On the mapFirst mapped by the U.S. Geological Survey
  14. 1933In the archiveVIEW WEST SHOWING EAST (FRONT) ELEVATION AND LOCATION AT JUNCTION OF ROUTES 62175 and 621…
  15. 1935Born hereJohn Taylor Gatto is born here
  16. 1946Born hereJay Chattaway is born here
  17. 1947Post officeThe Hazzard post office closes
  18. 1949Born hereMitch Daniels is born here
  19. 1950CensusPopulation peaks at 8,922
  20. 1958Born hereJim Renacci is born here
  21. 1976LandmarkEdward G. Acheson House named a National Historic Landmark
By decade

Monongahela, decade by decade

5 decades in the archive, from the 1810s to the 1990s. Scroll each row; tap a photo for its story.

1810s1 item
American Telegraph 7-5-18151815American Telegraph 7-5-1815Document
1880s–1930s5 items
1940 Census Enumeration District Maps - Pennsylvania - Washington County - Monongahela - ED 63-95, ED 63-96, ED 63-97, …18801940 Census Enumeration District Maps - Pennsylvania …1940 Census Enumeration District Maps - Pennsylvania - Washington County - Monongahela - ED 63-95, ED 63-96, ED 63-97, …18801940 Census Enumeration District Maps - Pennsylvania …Monongahela City, Pennsylvania, 19021902Monongahela City, Pennsylvania, 1902Monongahela City, Pennsylvania, 19021902Monongahela City, Pennsylvania, 1902VIEW WEST SHOWING EAST (FRONT) ELEVATION AND LOCATION AT JUNCTION OF ROUTES 62175 and 62161 - Taylor Run-Yorty Run Scho…1933VIEW WEST SHOWING EAST (FRONT) ELEVATION AND LOCATION…
1940s–1980snothing yet
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.
Add from your album
1990s1 item
View of historic Second Street brick launch ramp, adjacent to aquatorium - Second Street Launch Ramp, Second Street at …1994View of historic Second Street brick launch ramp, adj…
Date unknown1 to date
Second Street Launch Ramp, Second Street at Monongahela RiverDate?Second Street Launch Ramp, Second Street at Monongahe…
Today6 recent
Partial Solar Eclipse of 2024 seen from2024Partial Solar Eclipse of 2024 seen fromPA 88-837 nb, 136 wb in Monongahela (2), May 20242024PA 88-837 nb, 136 wb in Monongahela (2), May 2024PA 88-837 nb, 136 wb in Monongahela (1), May 20242024PA 88-837 nb, 136 wb in Monongahela (1), May 2024PA 88-837 nb at PA 136 west, May 20242024PA 88-837 nb at PA 136 west, May 2024PA 837 nb in Black Diamond, Monongahela, May 20242024PA 837 nb in Black Diamond, Monongahela, May 2024PA Route 43 exit 442006PA Route 43 exit 44
Then & now

Stand where they stood

No then-and-now pairs yet. Take a photo from the same spot as an old one and they appear here side by side.

1940 Census Enumeration District Maps - Pennsylvania - Washington County - Monongahela - ED 63-95, ED 63-96, ED 63-97, …
Retake this view1940 Census Enumeration District Maps - Pennsylvania - Washington County - Monongahela - ED 63-95, ED 63-96, ED 63-97, …, 1880

Find the spot, match the angle, and add your photo. It becomes the first then-and-now pair on Monongahela’s page.

Retake this view · +15
On the National Register

4 historic places in Monongahela

The country’s official list of buildings and places worth saving. One is a National Historic Landmark, the highest tier.

places listed
4
National Historic Landmark
1
Edward G. Acheson House
historic buildings protected
10
each building in a district counts
first listed
1976
Edward G. Acheson House
David Longwell HouseMonongahela Cemetery, built 1863Bethel African American Episcopal Church of Monongahela CityEdward G. Acheson House★
BuildingsSites★ landmark

Architectural styles listings

Gothic Revival2
Vernacular1
Italianate1
★ Landmark
Edward G. Acheson HouseVernacular
David Longwell HouseItalianate
Monongahela CemeteryGothic Revival · Built 1863
Bethel African American Episcopal Church of Monongahela CityGothic Revival

National Park Service, National Register of Historic Places. Photos from Wikimedia Commons, credited on each place’s page.

Famous people

18 famous people were born in Monongahela

Writers, athletes, leaders and more, ranked by how widely they’re known.

See all →
Mitch DanielsGovernor of Indiana · b. 1949
Jim RenacciAmerican politician · b. 1958
J
John Taylor GattoAmerican teacher and author · b. 1935
J
Jay ChattawayAmerican composer · b. 1946
Carl E. VuonoFormer U.S. Army general · b. 1934
C
Charles Harvey BollmanU.S. naturalist · b. 1868
Places that used to be

Lost post offices, old corners and burying grounds

Monongahela’s post office has been open since 1893. Two other post offices opened and closed inside today’s town.

Monongahela City
1837–1893
Monongahela
1893–today
Hazzard
1898–1947
18301930today
Hamlets and corners on the map
Black DiamondRiverview
1cemetery inside Monongahela
Monongahela

US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).

Help out

Finish Monongahela’s story

Most archives stop around 1920. The photos from after that are in family albums, not libraries.

Decades since 1900 with photos
00s10s20s30s40s50s60s70s80s90s
3 of 10 decades. The empty ones are waiting for someone’s album.
Date a photo1 archive item has no date. Guess the decade.+2Retake an old view1940 Census Enumeration District Maps -…: stand where they stood+15Share a family photoSign in to add one+10
Stories next door

History across the town line

Each neighbor’s History grade, on the same three inputs.

Carroll TownshipIts storyC+Forward TownshipIts storyB−New EagleIts storyB−Wickerham Manor-FisherIts storynot graded: under 1,000 residents or part of its townBaidlandIts storynot graded: under 1,000 residents or part of its town

Questions about Monongahela’s history

What year was Monongahela founded?

In 1769, according to Wikipedia’s history of the town. Monongahela’s post office opened in 1837, and the census of 1840 counted 752 people here.

How does Monongahela rank for history?

Monongahela is among the most historic 1% of U.S. towns, #41 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 Monongahela?

4 listings: 3 buildings, among them the Edward G. Acheson House (a National Historic Landmark since 1976), and 1 site. 10 historic buildings in all.

How old are the homes in Monongahela?

52% of Monongahela’s homes were built before 1940 (Census estimate, ±7.7 points), against a typical 18% for a Pennsylvania town; the median home was built in 1938.

Memory lane

What the archives can’t tell you, neighbors can.

Town Square →
Start a conversation
Sources

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 Wikimedia Commons (13), the Library of Congress (1), Wikidata (4), the National Register of Historic Places (4), 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) 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.