Key Largo’s post office opened in 1921, and 1 of its places is on the National Register
More historic than 16% of U.S. towns · #263 of 638 in Florida. What drives it
Most of Key Largo was built recently: 0.2% of its homes predate 1940 and the median home dates from 1983. Its Register listing is the African Queen. Below: 6 old photos and papers, maps from 1947 on, and the census since 1970.
The Key Largo post office opened in 1921, the earliest record of the town by name. Another post office, Rock Harbor (1915), opened inside today’s town and later closed.
First census: 2,866 in 19702020 census: 12,447105 years
How historic is Key Largo?
C−
More historic than 16% of U.S. towns, on its age, its old homes and the National Register.
Founding year: the first Key Largo post office (Blevins & Helbock, CC0).
History grade
What drives Key Largo’s History grade
On its age, its old homes and the National Register, Key Largo is more historic than 16% of U.S. towns, #263 of 638 in Florida. Its National Register listings hold the grade up; its share of homes from before 1940 pulls it down.
C−
HistoryA character grade: shown, never part of Key Largo’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 Key Largo’s 0.8 sits above most of its state (71% of Florida 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 D− to C. The pre-1940 share (±0.4 points) is firm at this size. 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 Key Largo’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
Key Largo’s post office has been open since 1921. Another post office, Rock Harbor, opened and closed inside today’s town.
Rock Harbor
1915–1952
Key Largo
1921–today
19101970today
Hamlets and corners on the map
Anglers ParkCoastal Waterway Park Mobile Home ParkGarden CoveKey Largo ParkNewportParadise Point Mobile Home ParkRiptide Trailer ParkRock HarborRock Harbor Marina East Mobile Home ParkSunset PointThompsonTravel Trailer Town
US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).
The story so far
Key Largo, in brief
Wikipedia doesn’t have a history of Key Largo yet. The photos, dates and memories neighbors add here are how it gets written.
Key Largo is an unincorporated area and census-designated place in Monroe County, Florida, United States, located on the island of Key Largo in the upper Florida Keys. The population was 12,447 at the 2020 census, up from 10,433 in 2010. The name comes from the Spanish Cayo Largo, or "long key". It is both the first island and town of the Florida Keys to be reached from the Overseas Highway to Key West. It was also the location of one of the stations of the Overseas Railroad.
Its first post office opened in 1921. Between the 2010 and 2020 censuses its population grew from 10,433 to 12,447 (+19%).
Intro from Wikipedia. Population: U.S. Census Bureau.
Timeline
Key Largo, 1915 to 1996
Woven from the archive, old maps, post office records, the National Register and the people born here.
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.
The Key Largo post office opened in 1921, the earliest record of the town by name (U.S. post office records).
How does Key Largo rank for history?
Key Largo is more historic than 16% of U.S. towns, #263 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.
What is on the National Register in Key Largo?
One place: the African Queen (listed 1992).
How old are the homes in Key Largo?
0.2% of Key Largo’s homes were built before 1940 (Census estimate), against a typical 0.6% for a Florida town; the median home was built in 1983.
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 (6), the National Register of Historic Places (1), 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.
1943
1953
1953
