1. On June 21, 1782, the Great Fire of Portland devastated the city's entire commercial district, destroying over 400 buildings and leaving more than 1,000 people homeless. The fire started in a bakery and quickly spread due to strong winds and dry weather conditions. It took several days to bring the flames under control.

2. June 21, 1812, marked the beginning of the War of 1812, a conflict between the United States and Great Britain that lasted for two and a half years. Maine played a significant role in the war, with several battles and skirmishes fought along its coast.

3. June 21, 1866, saw the establishment of the first public park in Maine, Deering Oaks in Portland. The park was named after businessman James Deering, who donated the land to the city for public use. Today, Deering Oaks is a popular spot for outdoor recreation and community events.

4. On June 21, 1970, the first official Earth Day was celebrated in Maine and across the country. The event was organized to raise awareness about environmental issues and promote conservation efforts. In Maine, numerous activities and events were held, including beach cleanups and tree-planting projects.

5. June 21, 2018, was a historic day for Maine as it became the ninth state to legalize recreational marijuana. The law allowed adults over the age of 21 to possess and consume marijuana for recreational purposes. The move was seen as a significant step forward for the state's cannabis industry and a potential boost for its economy.