Most of Congress was built recently: 0.0% of its homes predate 1940 and the median home dates from 1996. Below: 5 old photos and papers and maps from 1901 on.
The Congress post office opened in 1889, the earliest record of the town by name. Two smaller post offices, Weaver (1899) and Congress Junction (1906), opened inside today’s town and later closed.
2020 census: 1,811137 years
How historic is Congress?
D
More historic than 12% of U.S. towns, on its age, its old homes and the National Register.
Founding year: the first Congress post office (Blevins & Helbock, CC0).The full story ↓
History grade
What drives Congress’ History grade
On its age, its old homes and the National Register, Congress is more historic than 12% of U.S. towns. Its age holds the grade up; its share of homes from before 1940 pulls it down.
D
HistoryA character grade: shown, never part of Congress’ overall grade.
Few Arizona towns list much on the Register (a typical Arizona town has 0.1 per 10,000 residents, the U.S. 2.4), so Congress’ 0.0 sits below most of its state (29% of Arizona 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 (±1.3 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 Congress’ past
Read from the archive, the National Register and the record. The page puts what stands out first.
Lost post offices, old corners, places now gone and burying grounds
Congress’s post office has been open since 1889. Two other post offices opened and closed inside today’s town.
Congress
1889–today
Weaver
1899–1900
Congress Junction
1906–1938
18801950today
Hamlets and corners on the map
Congress JunctionPiedmont
Gone or out of use
Congress MinemineSenate Minemine
1cemetery inside Congress
Congress
US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).
Every building
Congress, building by building, 1901–1910
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.
1901Sheet 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.
Gold was discovered at the Congress Mine in 1884. By 1893, the Santa Fe, Prescott and Phoenix Railway passed within three miles of the mine, at Congress Junction. Congress boomed, and remained prosperous until the mid-1930s, when the mines closed. Total gold production at the Congress Mine exceeded $8 million at a production price of $20.67 per ounce – or about $400 million, at the 2007 price.
The post office moved to Congress Junction in 1938, where it remains. The community known as Congress is the old Congress Junction. Little remains at the original mining-camp townsite. The old Congress Cemetery is nearby.
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.
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 Congress post office opened in 1889, the earliest record of the town by name (U.S. post office records).
How does Congress rank for history?
Congress is more historic than 12% of U.S. towns. 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 Congress?
0.0% of Congress’ homes were built before 1940 (Census estimate, ±1.3 points), against a typical 0.4% for an Arizona town; the median home was built in 1996.
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 (5), the Library of Congress (1), Wikipedia, U.S. Geological Survey historical maps, 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.
1901
c. 1905
2007