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!

 

Celebrations Calendar

Longmont Legacy

with Erik Mason,
Longmont Museum Director

 

The Cheyenne, Arapaho and Ute were among the first peoples to live in what would become the St. Vrain Valley beginning thousands of years ago. In the 1800s, they began trading with people traveling through the region, including Latinos from New Mexico along the Trappers’ Trail.

 

The arrival of gold seekers in 1859 brought growing conflict and, ultimately, the military removal of the three tribes to reservations in Wyoming, southwestern Colorado and Oklahoma.

 

Starting in the 1950s, Indigenous peoples began returning to their ancestral homelands, and today Longmont is home to peoples from many tribal nations. The City’s relationship with the Northern Arapaho Tribe is one important effort to acknowledge this painful history and rebuild connections.

 

Latino and Indigenous communities continue to shape Longmont through their leadership, culture and presence.

In the Spotlight:

Indigenous and Latino History in Longmont 

 

Captions:

 

  1. Members of the Ute Nation in Roosevelt Park (then called Riding Park) in 1898.
  2. A sepia tone photograph of three women and two native American Indians on horses circa 1905-1920.
  3. Eloyeda Cardenas seated at an office desk, with a telephone, a filing cabinet, a bouquet of flowers, a coffee pot, and stacks of coffee cups visible. Published in the Times-Call on March 27, 1971.
  4. Black and white copy print of Ben Rodriguez at KLMO radio station. Ben is at the controls with a microphone in front of him. He is wearing a dark shirt with sleeves rolled-up.

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!