Longmont 155 | Colorado 150 | United States 250 - City of Longmont Skip to main content

Longmont 155 | Colorado 150 | United States 250

Historical photo of Main Street in Longmont CO with an overlaying logo marking the 155-150 and 250 USA anniversaries in 2026.

Celebrating 155 years of Longmont 

 

Did you know 2026 marks not one, not two, but three significant anniversaries?

In 2026, Longmont turns 155, Colorado will celebrate 150 years of Statehood, and the United States will mark 250 years since the signing of the Declaration of Independence. These triplet milestones are a rare and exciting opportunity to unite with our community in celebration of our past and to imagine our future together.

 

In Longmont, we will mark these anniversaries by exploring the history of our city and by hosting commemorative events and activities.

 

Check out the Celebrations Calendar below, invite your friends and family to join in the fun, and follow along as we journey through history and celebrate together!

 

Longmont Legacy

with Erik Mason,
Longmont Museum Director

 

Longmont began providing utility service to its residents in 1883 with the completion of a reservoir on Sunset hill and a network of underground pipes to provide fresh water to the town. In 1912, dissatisfaction with the private electric utility provider led to the construction of a hydroelectric power plant near Lyons and a municipally owned power system. The sanitary sewer system was built from 1904 to 1928, followed by trash collection starting in 1948. The most recent City utility, Nextlight high-speed internet, began operation in 2014. Very few cities provide all of these services to their residents.

 

Longmont modernized its government structure in 1961, when a community-based committee drafted a Home Rule Charter. The new charter provided for a City manager-Council form of government, which Longmont has had ever since.

In the Spotlight:

Longmont Utilities & History as a Home Rule Municipality

 

Captions:

 

  1. Black and white photographic print of the Home Rule Charter Convention Delegates for the City of Longmont from 1961. Photograph shows twenty-one people, seventeen men and four women, posed behind a u-shaped table. Seven people are seated and fourteen are standing. The table is covered with notebooks, papers, ashtrays and a coffee cup. In the background is a blackboard and a bulletin board, with a small sign reading “Colorado State Chamber of Commerce.” The names of all present are typewritten at the bottom on the print.
  2. The former Longmont Municipal Light & Power building, which remains well-known in Longmont today as the home of Cheese Importers, c. 1931, Hoffman Studio.
  3. City Electrical worker Dean Wadle near 400 Main St. installing a new streetlight as the city moved into its final phase of putting street lights on a single, regulated circuit. Published in the Times-Call on March 7, 1975.
  4. Longmont trash collectors empty a large trash container by hand in 1966.

Explore More History with Longmont’s Virtual Tours 

Is Sesquisemiquincentennial a real word?

logo for Longmont celebration of 155, CO150, USA 250 celebrationsIt sure is! You may see “Sesquisemiquincentennial” used around the state of Colorado this year. In 2026, Colorado celebrates its 150th anniversary of statehood (sesquicentennial) and the United State’s 250th anniversary (semiquincentennial) since the signing of the Declaration of Independence. Learn about more celebrations around the state on the History Colorado website.

 

Sesquicentennial + Semiquincentennial = Sesquisemiquincentennial

 

The City of Longmont, in collaboration with the American 250-Colorado 150 Commission, celebrates this unique anniversary year by looking back at Longmont’s 155 years of history. Follow this webpage to learn more about how you can celebrate with us, in person and online!