Colorado’s 150th anniversary

250th anniversary of the Declaration of Independence

You’re part of something big

America 250 - Colorado 150

Say it because you can: Semiquincentennial. Sesquicentennial. Sesquisemiquincentennial. 

In 2026, the United States will mark the 250th anniversary of the signing of the Declaration of Independence - the nation’s semiquincentennial. At the same time, Colorado will mark the 150th anniversary of its entrance into the Union–the state’s sesquicentennial. These combined anniversaries–our “Sesquisemiquincentennial”–provide an opportunity for us to come together with fellow Coloradans and Americans around our shared ideals.

The America 250 - Colorado 150 Commission was established to guide Colorado's twin commemorations in ways that enable all Coloradans to participate. We encourage you to plan community events, foster historic preservation, develop educational opportunities, gather in community, and more. Let’s commemorate our collective journey and look ahead to the trails we’ll explore together.


events calendar

We are thrilled to highlight the many ways Coloradans from all areas of the state are participating in the Sesquisemiquincentennial anniversary.

+ Feature Your event!

Share all of the exciting opportunities to participate in your local Sesquisemiquincentennial community events! Add your event to our searchable statewide calendar, and highlight how you are engaging with the commemoration.

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