1. In 1819, Maine officially became a state, separating from Massachusetts. The event is celebrated annually on March 15, which is known as Maine Statehood Day. However, September 1, 1819 is the date that Maine submitted its state constitution to Congress for approval.

2. In 1923, a hurricane struck the coast of Maine, causing widespread damage and claiming the lives of more than 200 people. The storm, known as the Cheniere Caminada Hurricane, also caused significant damage in other parts of New England.

3. In 1945, the Portsmouth Naval Shipyard in Kittery, Maine was the site of the signing of the instrument of surrender by Japanese officials, effectively ending World War II. The USS Missouri, on which the ceremony took place, is now a museum ship and is open to visitors.

4. In 2006, a magnitude 4.2 earthquake struck southern Maine, causing minor damage and rattling nerves throughout the region. Maine is not typically associated with seismic activity, although small quakes can occur from time to time.

5. In 2016, Maine became the first state in the US to adopt ranked-choice voting for statewide primary and general elections. The system allows voters to rank candidates in order of preference, rather than simply choosing one. The use of ranked-choice voting has been controversial, with some arguing that it helps to ensure that the winner of an election has majority support, while others argue that it can be confusing and complicated for voters.