Hamilton’s post office opened in 1890, and 33% of its homes were built before 1940
More historic than 86% of U.S. towns · #5 of 42 in Montana. What drives it
28 places in town are on the National Register, among them three historic districts with 204 buildings between them. Below: 13 old photos and papers, maps from 1893 on, and the census since 1880.
On its age, its old homes and the National Register, Hamilton is more historic than 86% of U.S. towns, #5 of 42 in Montana. Its National Register listings hold the grade up; its age pulls it down.
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HistoryA character grade: shown, never part of Hamilton’s overall grade.
Montana towns list more on the Register than most of the country (a typical Montana town has 12.7 per 10,000 residents, the U.S. 2.4), so Hamilton’s 474 sits above most of its state (94% of Montana towns have fewer) while its 242 historic buildings outnumber those of 94% of U.S. towns.
How sure. Graded on any two of the three inputs instead, the letter would range from B+ to A+. The pre-1940 share is a Census survey estimate (±8.8 points). 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 Hamilton’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
National Park Service, National Register of Historic Places. Photos from Wikimedia Commons, credited on each place’s page.
Every building
Hamilton, building by building, 1893–1914
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.
Hamilton was founded by copper king Marcus Daly in the late 19th century. It was named for J.W. Hamilton, who provided the right-of-way to the railroad. Daly is said to have wanted to begin business in Grantsdale, but was denied the opportunity.
In the summer of 2000, forest fires throughout the Bitterroot Valley filled the area with smoke and prompted the evacuation of many residents. President Clinton declared a state of emergency in the area and dispatched National Guard troops to assist with fighting the fires.
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 Hamilton post office opened in 1890, the earliest record of the town by name (U.S. post office records).
How does Hamilton rank for history?
Hamilton is more historic than 86% of U.S. towns, #5 of 42 in Montana. 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 Hamilton?
28 listings: 25 buildings, among them the Canyon Creek Laboratory of the U.S. Public Health Service (listed 1970, the first), and 3 historic districts, the Hamilton Commercial Historic District, the Hamilton Southside Residential Historic District and the Rocky Mountain Laboratory Historic District, with 204 contributing buildings. 242 historic buildings in all.
How old are the homes in Hamilton?
33% of Hamilton’s homes were built before 1940 (Census estimate, ±8.8 points), against a typical 13% for a Montana town; the median home was built in 1976.
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 the Library of Congress (13), Wikidata (11), the National Register of Historic Places (28), 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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