More historic than 18% of U.S. towns · #521 of 847 in California. What drives it
Most of El Cajon was built recently: 2% of its homes predate 1940 and the median home dates from 1974. Below: maps from 1890 on and the census since 1920.
The El Cajon post office opened in 1878, the earliest record of the town by name. Another post office, Bostonia (1894), opened inside today’s city and later closed.
First census: 469 in 19202020 census: 106,215148 years
How historic is El Cajon?
C−
More historic than 18% of U.S. towns, on its age, its old homes and the National Register.
Founding year: the first El Cajon post office (Blevins & Helbock, CC0).The full story ↓
History grade
What drives El Cajon’s History grade
On its age, its old homes and the National Register, El Cajon is more historic than 18% of U.S. towns, #521 of 847 in California. Its age holds the grade up; its share of homes from before 1940 pulls it down.
C−
HistoryA character grade: shown, never part of El Cajon’s overall grade.
Among the 400 U.S. cities of 100,000 or more, El Cajon ranks #350 on History.
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 El Cajon’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.
Newer cities are common at El Cajon’s size: in the typical U.S. city of 100,000 or more, 5% of homes predate 1940.
How sure. Graded on any two of the three inputs instead, the letter would range from D to C−. The pre-1940 share (±0.6 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 El Cajon’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
During Spanish rule (1769–1821), the government encouraged settlement of territory now known as California by the establishment of large land grants called ranchos, from which the English word ranch is derived. Land grants were made to the Roman Catholic Church, which set up numerous missions throughout the region. In the early 19th century, mission padres' search for pastureland led them to the El Cajon Valley. Surrounding foothills served as a barrier to straying cattle and a watershed to gather the sparse rainfall. For years, the pasturelands of El Cajon supported the cattle herds of the mission and its native Indian converts.
Fire insurance maps drew every building, what it was made of and what it was used for, so insurers could price the risk of fire. Pick a year, then a sheet.
1890Sheet 1 of 1
Edition
Sheets
BrickWoodStone
Sanborn Map Company, via the Library of Congress. Editions published in 1930 or earlier, which are in the public domain.
People over time
El Cajon, census by census
Grew from 469 people in 1920 to 106,215 in 2020, more than tenfold.
11 censuses, 1920–2020.
U.S. Census Bureau decennial counts, from the census table on El Cajon’s Wikipedia page.
Famous people
23 famous people were born in El Cajon
Writers, athletes, leaders and more, ranked by how widely they’re known.
The El Cajon post office opened in 1878, the earliest record of the town by name (U.S. post office records).
How does El Cajon rank for history?
El Cajon is more historic than 18% of U.S. towns, #521 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.
How old are the homes in El Cajon?
2% of El Cajon’s homes were built before 1940 (Census estimate), against a typical 3.4% for a California town; the median home was built in 1974.
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 (7), Wikipedia, 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), the USGS Geographic Names Information System and Sanborn fire insurance maps (Library of Congress). Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
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