1. On November 17, 1917, the United States officially entered World War I. Delaware played a significant role in the war effort, with over 3,000 Delawareans serving in the military.

2. On November 17, 1969, the Dover International Speedway opened for its first race. Known as the "Monster Mile," the track has since hosted numerous NASCAR events and is a popular destination for racing fans.

3. On November 17, 1988, a fire at the Dupont Plaza Hotel in San Juan, Puerto Rico killed 97 people, including nine Delawareans. The tragedy led to significant changes in fire safety regulations and procedures.

4. On November 17, 1993, the Delaware Supreme Court ruled that the state's ban on gay and lesbian relationships was unconstitutional. The decision paved the way for the legalization of same-sex marriage in Delaware in 2013.

5. On November 17, 2018, the University of Delaware's football team won its first conference championship in over a decade. The Blue Hens defeated Stony Brook in the Colonial Athletic Association championship game, earning a spot in the NCAA playoffs.