Each edition grades its towns against each other only.
More historic than 5% of U.S. towns. What drives it
Most of Carroll Valley was built recently: 2% of its homes predate 1940 and the median home dates from 1993. Below: maps from 1942 on and the census since 1980.
Carroll Valley dates its founding to 1974 (Wikidata). The census first counted it in 1980.
More historic than 5% of U.S. towns, on its age, its old homes and the National Register.
On its age, its old homes and the National Register, Carroll Valley is more historic than 5% of U.S. towns. Its National Register listings hold the grade up; its age pulls it down.
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 Carroll Valley’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.
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 →
Read from the archive, the National Register and the record. The page puts what stands out first.
The first neighbors to add old photos shape how Carroll Valley’s history is told.
Wikipedia doesn’t have a history of Carroll Valley yet. The photos, dates and memories neighbors add here are how it gets written.
Carroll Valley is a borough in Adams County, Pennsylvania, United States. The population was 3,940 at the 2020 census.
Carroll Valley was established in 1974. Its population held steady between the last two censuses: 3,876 in 2010, 3,940 in 2020.
Intro from Wikipedia. Population: U.S. Census Bureau.
Every edition of the U.S. Geological Survey’s map of Carroll Valley. Tap a year, or press play to watch the town change.
U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of Carroll Valley.
Grew from 817 people in 1980 to 3,940 in 2020, 4 times over.
5 censuses, 1980–2020.
U.S. Census Bureau decennial counts, from the census table on Carroll Valley’s Wikipedia page.
Nobody well known was born in Carroll Valley itself, so here are the best known from just nearby.
Each neighbor’s History grade, on the same three inputs.
In 1974, according to Wikidata. the census of 1980 counted 817 people here.
Carroll Valley is more historic than 5% 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.
2% of Carroll Valley’s homes were built before 1940 (Census estimate, ±2.4 points), against a typical 18% for a Pennsylvania town; the median home was built in 1993.
What the archives can’t tell you, neighbors can.
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 (2), 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.
2025
2025
