More historic than 13% of U.S. towns · #51 of 59 in Idaho. What drives it
Most of Ammon was built recently: 1% of its homes predate 1940 and the median home dates from 2004. Below: maps from 1924 on and the census since 1910.
Founding year: Wikidata; Wikipedia’s history section gives the same year. First post office: 1898.The full story ↓
History grade
What drives Ammon’s History grade
On its age, its old homes and the National Register, Ammon is more historic than 13% of U.S. towns, #51 of 59 in Idaho. Its age holds the grade up; its share of homes from before 1940 pulls it down.
D
HistoryA character grade: shown, never part of Ammon’s overall grade.
Idaho towns list more on the Register than most of the country (a typical Idaho town has 8.4 per 10,000 residents, the U.S. 2.4), so Ammon’s 0.0 sits below most of its state (14% of Idaho towns have fewer) while its 0 listings outnumber those of 23% 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 (±0.7 points) is firm at this size. Two sources give 1888.
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 →
What stands out about Ammon’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
Ammon was founded by members of the Church of Jesus Christ of Latter-day Saints in 1888. It was originally called South Iona because it was the dependent branch in the south end of the Iona, Idaho ward. The area was made a ward in the church in 1889 with Arthur M. Rawson as bishop, who renamed the town in honor of Ammon, a figure in the LDS book of scripture, the Book of Mormon. Since it was now independent of the Iona Ward, a new name seemed appropriate. On February 9, 1893, the name of the town was changed from South Iona Ward to Ammon.
By 1930 the village of Ammon had 270 inhabitants, but the total district of Ammon, which is how the name is usually used and is closer to the modern borders, had a population of about 1100.
In 1888, according to Wikidata and Wikipedia’s history of the town. Ammon’s post office opened in 1898, and the census of 1910 counted 214 people here.
How does Ammon rank for history?
Ammon is more historic than 13% of U.S. towns, #51 of 59 in Idaho. 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 Ammon?
1% of Ammon’s homes were built before 1940 (Census estimate), against a typical 8.5% for an Idaho town; the median home was built in 2004.
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, 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.
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