1. On May 20, 1638, Swedish settlers established Fort Christina in present-day Wilmington, Delaware. This was the first permanent European settlement in the Delaware Valley and would eventually become part of the New Sweden colony.

2. The infamous Patty Cannon, a notorious slave trader and criminal, was arrested on May 20, 1829, in Maryland after kidnapping several free African Americans in Delaware. Cannon was eventually tried and convicted for her crimes, and the case brought attention to the horrors of the illegal slave trade.

3. On May 20, 1915, the DuPont Powder Company's plant in Wilmington, Delaware, exploded, killing over 30 people and injuring hundreds. The explosion was caused by an accident in one of the nitrocellulose drying rooms, and the resulting blast was felt for miles around.

4. The University of Delaware was founded on May 20, 1833, as Newark College. It was originally affiliated with the Methodist Episcopal Church and was located in Newark, Delaware. The school would eventually become the University of Delaware and is now a major public research university with over 24,000 students.

5. Delaware's first astronaut, Gregory Jarvis, was born on May 24, 1944. Jarvis attended the University of Buffalo and later joined NASA, where he trained as a payload specialist for the Space Shuttle program. In 1986, Jarvis was one of seven crew members who died in the Space Shuttle Challenger disaster.