1. Washington became a state on November 11, 1889, but June 1 marks the first day of Washington's statehood in 1889.

2. In 1962, Seattle's World's Fair, also known as the Century 21 Exposition, opened on June 1. The fair brought in over 10 million visitors and led to the construction of the iconic Space Needle.

3. On June 1, 1926, Air Mail service began in the United States. The first flight carried mail from Pasco to Elko, Nevada, passing over Spokane and other cities in Washington state.

4. In 1812, the United States declared war on Great Britain. This event would eventually lead to the Battle of Seattle on June 1, 1856 during the Puget Sound War.

5. On June 1, 1974, the state of Washington adopted its official state song, "Washington, My Home." The song, written by Helen Davis and arranged by Stuart Churchill, celebrates the state's natural beauty and cultural heritage.