1. In 1941, the United States Navy began construction on a Naval Air Station in Whidbey Island, Washington. The base was designed to house the Pacific Fleet's patrol wing, which played a critical role in defending the Pacific coastline during World War II.

2. In 1973, the Washington State Supreme Court ruled that the death penalty violated the state's constitution. The ruling resulted in the commutation of all death sentences to life imprisonment.

3. In 1989, a magnitude 6.0 earthquake struck the state of Washington. The earthquake caused significant damage to buildings and infrastructure in the city of Seattle and surrounding areas.

4. In 1996, the Seattle Mariners baseball team played in their first-ever American League Championship Series game. Despite losing the series to the New York Yankees, the Mariners' postseason run was a significant moment in the team's history.

5. In 2018, Washington became the second state in the United States to legalize the recreational use of marijuana. The move followed a 2012 voter initiative that legalized the use of medical marijuana in the state.