1. Colorado became the 38th state on May 9, 1876. This day is celebrated as Colorado Day.
2. On May 9, 1945, the Germans surrendered to the Allied forces, marking the end of World War II in Europe. This event was celebrated widely in Colorado, as it was across the world.
3. May 9, 1955, was a significant day in Colorado's transportation history when the longest tunnel in the state, the Eisenhower Tunnel on I-70, was officially opened.
4. On May 9, 1974, the University of Northern Colorado in Greeley awarded an honorary doctorate to John F. Kennedy in recognition of his contribution to international affairs.
5. May 9, 2007, marked the official opening of the Denver Art Museum's Frederic C. Hamilton building, a significant addition to the city's cultural landscape. The building's striking architecture and impressive collection of art have made it a popular tourist destination.