Each edition grades its towns against each other only.
More historic than 11% of U.S. towns · #664 of 847 in California. What drives it
Most of Harmony Grove was built recently: 1% of its homes predate 1940 and the median home dates from 2014. Below: maps from 1893 on.
More historic than 11% of U.S. towns, on its age, its old homes and the National Register.
On its age, its old homes and the National Register, Harmony Grove is more historic than 11% of U.S. towns, #664 of 847 in California. Its National Register listings hold the grade up; its share of homes from before 1940 pulls it down.
Few California towns list much on the Register (a typical California town has 0.0 per 10,000 residents, the U.S. 2.4), so Harmony Grove’s 0.0 sits below most of its state (31% of California towns have fewer) while its 0 listings outnumber those of 23% of U.S. towns.
Founding year: our sources. 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 Harmony Grove’s history is told.
Every edition of the U.S. Geological Survey’s map of Harmony Grove. 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 Harmony Grove.
Wikipedia doesn’t have a history of Harmony Grove yet. The photos, dates and memories neighbors add here are how it gets written.
Harmony Grove is an unincorporated community and census-designated place (CDP) in San Diego County, California, United States. Per the 2020 census, the population was 2,079.
Intro from Wikipedia. Population: U.S. Census Bureau.
Nobody well known was born in Harmony Grove itself, so here are the best known from just nearby.
Places and cemeteries from the USGS Geographic Names Information System (2021).
Each neighbor’s History grade, on the same three inputs.
Harmony Grove is more historic than 11% of U.S. towns, #664 of 847 in California. 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.
1% of Harmony Grove’s homes were built before 1940 (Census estimate, ±2.0 points), against a typical 3.4% for a California town; the median home was built in 2014.
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 (3), U.S. Geological Survey historical maps 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.
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