More historic than 10% of U.S. towns · #347 of 638 in Florida. What drives it
Most of Keystone was built recently: 0.8% of its homes predate 1940 and the median home dates from 1999. Below: maps from 1943 on and the census since 2000.
On its age, its old homes and the National Register, Keystone is more historic than 10% of U.S. towns, #347 of 638 in Florida. Its National Register listings hold the grade up; its share of homes from before 1940 pulls it down.
D
HistoryA character grade: shown, never part of Keystone’s overall grade.
Few Florida towns list much on the Register (a typical Florida town has 0.0 per 10,000 residents, the U.S. 2.4), so Keystone’s 0.0 sits below most of its state (33% of Florida towns have fewer) while its 0 listings outnumber those of 23% of U.S. towns.
How sure. Graded on two of the three inputs, so a change in either one moves the letter more than it would with three. The pre-1940 share (±0.6 points) is firm at this size.
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 →
What stands out about Keystone’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
Another post office, Keystone Park, opened and closed inside today’s town.
Hamlets and corners on the map
AlldredgeAngel Farms EstatesArbor LakesBelmack AcresC And B EstatesCanterburyCanterbury Heights at the EaglesCanterbury North at the EaglesCanterbury VillageCanterbury WoodsCimino EstatesCitrus GreenClarkmereCouncil CrestCrippenwoodCypress Lake EstatesDalyDolce VitaDurangoEcho Lake EstatesEstates of Lake AliceEstates of Rock LakeFarmingtonFern Glen
US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).
Help out
Start Keystone’s collection
The first neighbors to add old photos shape how Keystone’s history is told.
Decades since 1900 with photos
00s10s20s30s40s50s60s70s80s90s
0 of 10 decades. The empty ones are waiting for someone’s album.
Wikipedia doesn’t have a history of Keystone yet. The photos, dates and memories neighbors add here are how it gets written.
Keystone is an unincorporated census-designated place in Hillsborough County, Florida, United States. The Keystone area was first settled in the middle 1800s by the W.M. Mobley Family who migrated from Savannah, Georgia. The region has evolved from citrus and farming into a rural retreat of many lake homes and ranches. As of the 2020 census, Keystone had a population of 25,211. The ZIP Codes encompassing the CDP area are 33556 and 33558.
Between the 2010 and 2020 censuses its population grew from 24,039 to 25,211 (+5%).
Intro from Wikipedia. Population: U.S. Census Bureau.
Timeline
Keystone, 1884 to 1943
Woven from the archive, old maps, post office records, the National Register and the people born here.
Keystone is more historic than 10% of U.S. towns, #347 of 638 in Florida. 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.
How old are the homes in Keystone?
0.8% of Keystone’s homes were built before 1940 (Census estimate), against a typical 0.6% for a Florida town; the median home was built in 1999.
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 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.
