1. On September 10, 1884, the cornerstone for the State Capitol Building in Denver was laid. The building would become an iconic symbol of Colorado, with its distinctive gold dome and neoclassical architecture.

2. In 1918, on September 10, the first cases of the Spanish influenza were reported in Colorado. The pandemic would go on to claim the lives of over 8,000 Coloradans and millions worldwide.

3. The devastating Colorado Labor Wars reached a turning point on September 10, 1913, when a bomb exploded at the home of Governor Elias Ammons. The bombing was linked to the ongoing conflict between striking miners and the Colorado National Guard, leading to further violence and the eventual resignation of the governor.

4. On September 10, 1988, the Four Corners Monument was officially recognized as a national historic landmark. The monument marks the only point in the United States where four states - Colorado, New Mexico, Arizona, and Utah - meet at a single point.

5. In 1969, on September 10, the Denver Broncos played their first NFL game ever. The team, founded just two years prior, lost 27-10 to the Boston Patriots at Fenway Park. However, the Broncos would go on to become a beloved institution in Colorado and the NFL, winning three Super Bowls and nurturing some of the greatest players in football history.