The story
Read it all →How Monaghan Township came to be
From Wikipedia’s history of Monaghan Township.
The Gilbert Bridge was added to the National Register of Historic Places in 1989.
Text from Wikipedia, licensed CC BY-SA 4.0.
BHistory
History · Monaghan Township
Monaghan Township’s post office opened in 1888, and 19% of its homes were built before 1940
More historic than 57% of U.S. towns · #632 of 1,035 in Pennsylvania. What drives it
Its Register listing is the Gilbert Bridge. Below: maps from 1906 on and the census since 2000.
1888first post office
1on the National Register
19%homes built before 1940
Quick answers
How Monaghan Township began
When was Monaghan Township founded?
1888
The Monaghan Township post office opened in 1888, the earliest record of the town by name. Two smaller post offices, Sidonsburg (1822) and Monaghan (1888), opened inside today’s town and later closed.
First census: 2,132 in 20002020 census: 2,675138 years
How historic is Monaghan Township?
B
What drives the grade ↓More historic than 57% of U.S. towns, on its age, its old homes and the National Register.
Founding year: the first Monaghan Township post office (Blevins & Helbock, CC0).The full story ↓
History grade
What drives Monaghan Township’s History grade
On its age, its old homes and the National Register, Monaghan Township is more historic than 57% of U.S. towns, #632 of 1,035 in Pennsylvania. Its share of homes from before 1940 holds the grade up; its age pulls it down.
B
HistoryA character grade: shown, never part of Monaghan Township’s overall grade.
Founding era1888, from the first post office: founded 1850–1899, an older era than 37% of U.S. townsC+Homes built before 194019.0% of homes (±8.4) · typical PA town 17.7% · U.S. 8.4%B+National Register1 listing, 3.7 per 10,000 residents · typical PA town 2.1 · U.S. 2.4B
All U.S. towns we grade (21,289)Ahead of 57%
NewerOlder
Pennsylvania towns of 2,500+ (1,035)Ahead of 39%
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 Monaghan Township’s 3.7 sits near the middle of its state (63% 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 B+. The pre-1940 share is a Census survey estimate (±8.4 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 Monaghan Township’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
A history waiting to be writtenNo old photos of Monaghan Township are in the public archives yet. The rest are in attics and albums.Lost villages2 post offices opened and closed inside today’s Monaghan Township, and 4 old place names are still on the map.On the map since 19067 editions of the USGS map, 1906 to 1999. Watch Monaghan Township change.
★ What stands out · Help out
Start Monaghan Township’s collection
The first neighbors to add old photos shape how Monaghan Township’s history is told.
Decades since 1900 with photos
00s10s20s30s40s50s60s70s80s90s
0 of 10 decades. The empty ones are waiting for someone’s album.Places that used to be
Lost post offices, old corners, places now gone and burying grounds
Two other post offices opened and closed inside today’s town.
Sidonsburg
Monaghan
18201920today
Hamlets and corners on the map
AndersontownMemphord EstatesMount PleasantSiddonsburg
Gone or out of use
Monaghan P ObuildingVogelsong Airportairport
1cemetery inside Monaghan Township
Myers
US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).
On the map
Monaghan Township on the map, 1906 to 1999
Every edition of the U.S. Geological Survey’s map of Monaghan Township. Tap a year, or press play to watch the town change.
1906New Cumberland sheet · 1:62,500U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of Monaghan Township.
Timeline
Monaghan Township, 1822 to 1920
Woven from the archive, old maps, post office records, the National Register and the people born here.
By decade
No old photos in the archives yet
Weddings on Main Street, storms, parades, school pictures, the old store. If it’s in your family album, it belongs here.
Be the first to add onePhotograph a print flat, in daylight, no flash.
Add from your albumOn the National Register
1 historic place in Monaghan Township
The country’s official list of buildings and places worth saving.
place listed
1
National Historic Landmarks
0
none yet
historic buildings protected
1
each building in a district counts
first listed
1989
Gilbert Bridge
Structures
Architectural styles listings
Pratt through Truss1
National Park Service, National Register of Historic Places. Photos from Wikimedia Commons, credited on each place’s page.
People over time
Monaghan Township, census by census
Between 2,132 and 2,676 people in every census since 2000.
3 censuses, 2000–2020.
U.S. Census Bureau decennial counts, from the census table on Monaghan Township’s Wikipedia page.
Stories next door
History across the town line
Each neighbor’s History grade, on the same three inputs.
Questions about Monaghan Township’s history
What year was Monaghan Township founded?
The Monaghan Township post office opened in 1888, the earliest record of the town by name (U.S. post office records).
How does Monaghan Township rank for history?
Monaghan Township is more historic than 57% of U.S. towns, #632 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 Monaghan Township?
One place: the Gilbert Bridge (listed 1989).
How old are the homes in Monaghan Township?
19% of Monaghan Township’s homes were built before 1940 (Census estimate, ±8.4 points), against a typical 18% for a Pennsylvania town; the median home was built in 1983.
Memory lane
What the archives can’t tell you, neighbors can.
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 the National Register of Historic Places (1), Wikipedia, 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.