1. In 1859, the first Colorado Territory Legislature convened in Denver for an 18-day session. This marked the beginning of Colorado's journey towards statehood.

2. On March 20, 1933, President Franklin D. Roosevelt signed the Beer and Wine Revenue Act, effectively legalizing the sale of beer and wine with a low alcohol content. This was a significant moment for Colorado's thriving brewing industry, which had been impacted by Prohibition.

3. In 1974, a tornado touched down in Windsor, Colorado on March 20, causing widespread damage and several fatalities. This event highlighted the importance of preparedness and safety measures for natural disasters in the state.

4. March 20, 1987 marked the opening day of the Colorado Rockies' first-ever Major League Baseball season. The team played their first official game against the Houston Astros in the Astrodome.

5. In 2013, Colorado Governor John Hickenlooper signed into law two bills legalizing the use of recreational marijuana in the state. This made Colorado the first state to do so, setting a precedent for other states to follow suit. The bills went into effect on January 1, 2014.