1. In 1859, the territorial legislature of Colorado officially organized the Jefferson Territory, which encompassed present-day Colorado, Wyoming, and parts of Nebraska and Utah. The territory was named after Thomas Jefferson, the third president of the United States.

2. In 1860, the first Colorado newspaper, the Rocky Mountain News, was established in Denver by William Byers. The newspaper served as a major source of news and political commentary in Colorado for over a century before ceasing publication in 2009.

3. In 1874, the Colorado State Capitol building was completed after several years of construction. The building is located in the heart of downtown Denver and features a distinctive gold dome that serves as a symbol of the state's mining heritage.

4. In 1898, the Spanish-American War began, and over 15,000 Colorado soldiers served in the conflict. Many Colorado troops fought in Cuba and the Philippines, and several were awarded the Medal of Honor for their bravery in battle.

5. In 1995, the Oklahoma City bombing occurred, killing 168 people and injuring hundreds more. Timothy McVeigh, the perpetrator, was arrested and later executed for his role in the attack. Notably, one of the victims was a 6-year-old girl named Ashley Eckels, who was visiting from Colorado with her family.