Guest, Sign inJoin

Post to Delmont

We’ll email a one-tap link to publish your post. No password, and nothing is public until you click it.
Already a member? Sign in
–Not graded
History · Delmont

Delmont dates to 1886, and 46% of its homes were built before 1940

5 places in town are on the National Register. Below: maps from 1903 on and the census since 1910.

1886founded
5on the National Register
46%homes built before 1940
Add an old photoShare a memory
Quick answers

How Delmont began

When was Delmont founded?

1886

Delmont dates its founding to 1886 (Wikipedia’s history). The census first counted it in 1910.

First census: 369 in 19102020 census: 153140 years
Founding year: Wikipedia. First post office: 1887.

What stands out about Delmont’s past

Read from the archive, the National Register and the record. The page puts what stands out first.

A history waiting to be writtenNo old photos of Delmont are in the public archives yet. The rest are in attics and albums.Boom and bustPeaked at 518 in 1920; 153 people lived here in 2020.Old housesHalf of Delmont’s homes were built before 1943.Mapped building by building3 fire insurance maps, 1903 to 1918, drew every building in Delmont.
★ What stands out · Help out

Start Delmont’s collection

The first neighbors to add old photos shape how Delmont’s history is told.

Decades since 1900 with photos
00s10s20s30s40s50s60s70s80s90s
0 of 10 decades. The empty ones are waiting for someone’s album.
Share a family photoSign in to add one+10
People over time

Delmont, census by census

0100200300400500192019401960198020002020Peak: 518

Peaked at 518 in 1920; 153 people lived here in 2020.

12 censuses, 1910–2020.

U.S. Census Bureau decennial counts, from the census table on Delmont’s Wikipedia page.

The story so far

Delmont, in brief

Wikipedia doesn’t have a history of Delmont yet. The photos, dates and memories neighbors add here are how it gets written.

Delmont is a city in southeastern Douglas County, South Dakota, United States. The population was 153 at the 2020 census. Delmont was laid out in 1886. The Onion House, named for his onion shaped metallic dome and located in Delmont, is listed on the list of National Register of Historic Places since 1987. Also included on the same historic marker is Bluebird Locker, a local business in Delmont known for its “Delmont Sausage” but also serves as a butchery for other types of meats.

Delmont was established in 1886. Between the 2010 and 2020 censuses its population fell from 234 to 153 (-35%).

Intro from Wikipedia. Population: U.S. Census Bureau.

Timeline

Delmont, 1886 to 1979

Woven from the archive, old maps, post office records, the National Register and the people born here.

  1. 19th century
  2. 1886
    FoundingDelmont is established
  3. 1887Post officeThe Delmont post office opens
  4. 20th century
  5. 1902BuiltThomas Lenehan House is built
  6. 1920CensusPopulation peaks at 518
  7. 1979On the mapFirst mapped by the U.S. Geological Survey
By decade

Delmont, decade by decade

Today11 recent
Delmont Water Tower2010Delmont Water TowerDelmont Pump House 22010Delmont Pump House 2Delmont Pump House 12010Delmont Pump House 1Delmont Opera Block2010Delmont Opera BlockDelmont Onion House 22010Delmont Onion House 2Delmont Onion House 12010Delmont Onion House 1Delmont Hope Lutheran2010Delmont Hope LutheranDelmont Firefighter Memorial2010Delmont Firefighter MemorialDelmont Fire Dept2010Delmont Fire DeptDelmont City Finance Office2010Delmont City Finance OfficeDelmont Blue Bird Locker2010Delmont Blue Bird Locker
On the map

Delmont on the map, 1979 to 1986

Every edition of the U.S. Geological Survey’s map of Delmont. Tap a year, or press play to watch the town change.

Delmont on the 1979 USGS mapDelmont on the 1986 USGS map1979Delmont sheet · 1:24,000

U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of Delmont.

Every building

Delmont, building by building, 1903–1918

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.

Delmont fire insurance map, 1903, sheet 11903Sheet 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.

On the National Register

5 historic places in Delmont

The country’s official list of buildings and places worth saving.

places listed
5
National Historic Landmarks
0
none yet
historic buildings protected
5
each building in a district counts
first listed
1988
Thomas Lenehan House
Thomas Lenehan House, built 1902Stevens Opera BlockDelmont Public SchoolDelmont PumphouseDelmont State Bank
Buildings

Architectural styles listings

Queen Anne1
Late 19th and Early 20th Century American Movements1
Commercial Style1
Vernacular Collegiate Gothic1
Commercial1
Thomas Lenehan HouseQueen Anne · Built 1902
Stevens Opera BlockLate 19th and Early 20th Century American Movements
Delmont Public SchoolVernacular Collegiate Gothic
Delmont PumphouseBuilding
Delmont State BankCommercial

National Park Service, National Register of Historic Places. Photos from Wikimedia Commons, credited on each place’s page.

Famous people

Famous people close to Delmont

Nobody well known was born in Delmont itself, so here are the best known from just nearby.

See all →
Riley ReiffAmerican football player · b. 1988
Doug EggersAmerican football player · b. 1930
E
Emily St. JamesAmerican writer and critic · b. 1982
G
George FaustAmerican football player · b. 1917
J
John C. FlanaganAmerican psychologist · b. 1906
Peirson Mitchell HallUnited States federal judge · b. 1894

Questions about Delmont’s history

What year was Delmont founded?

In 1886, according to Wikipedia’s history of the town. Delmont’s post office opened in 1887, and the census of 1910 counted 369 people here.

What is on the National Register in Delmont?

5 listings: 5 buildings, among them the Thomas Lenehan House (listed 1988, the first).

Memory lane

What the archives can’t tell you, neighbors can.

Town Square →
Start a conversation
Sources

Where this page comes from

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). How TownRatings grades history →

From Wikimedia Commons (11), Wikidata (5), the National Register of Historic Places (5), 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.