1. In 1915, a German submarine sank the British steamship Lusitania off the coast of Ireland, killing 1,198 people. Among the passengers were 128 Americans, leading to increased calls for the United States to enter World War I.

2. In 1954, the United States Supreme Court handed down its landmark decision in Brown v. Board of Education, which declared racial segregation in public schools unconstitutional. The ruling paved the way for the civil rights movement and helped end legal segregation in the United States.

3. In 1975, President Gerald Ford declared an end to the United States' involvement in the Vietnam War. The conflict had claimed the lives of over 58,000 Americans and had deeply divided the country.

4. In 2000, the United States and Canada signed the "Heart of the Continent Partnership," an agreement to protect the natural resources and wildlife of the North American heartland. The partnership covers an area of over 2 million square miles, and aims to promote sustainable development and environmental conservation.

5. In 2013, the Seattle Seahawks officially retired the jersey of legendary wide receiver Steve Largent. Largent played for the Seahawks from 1976 to 1989, and set numerous records during his career. He was inducted into the Pro Football Hall of Fame in 1995.