1. On June 20, 1902, Maine Senator William P. Frye presented the Frye amendment to the Senate, which would have allowed the United States to acquire the Philippine Islands from Spain. The amendment was controversial and ultimately failed to pass.

2. In 1936, the Maine State Police was established on June 20. The agency is responsible for enforcing state laws and providing assistance to other law enforcement agencies in the state.

3. On June 20, 1974, Maine became the first state to institute a bottle bill, which mandated that a five-cent deposit be added to most beverage containers. The initiative was designed to promote recycling and has since been adopted by nine other states.

4. In 2013, the Maine Senate passed a bill on June 20 to allow same-sex marriage in the state. The bill was later signed into law by Governor Paul LePage, making Maine the eighth state to legalize same-sex marriage.

5. On June 20, 2019, Maine Governor Janet Mills signed legislation to establish a state holiday in honor of Juneteenth, which commemorates the end of slavery in the United States. Maine became the 47th state to recognize Juneteenth as a holiday.