1. Missouri became the 24th state of the United States on May 30, 1821. The state was admitted as a slave state and played a crucial role in the Civil War.

2. On May 30, 1883, the world's first electric power distribution system was installed in downtown St. Louis. The system was an incredible technological advancement at the time and paved the way for modern power distribution systems.

3. On May 30, 1901, Casey Jones, the famous railroad engineer, died in a train collision in Vaughn, Mississippi. Jones was born in southeast Missouri and is considered a folk hero for his daring acts while driving trains.

4. The Gateway Arch in St. Louis was dedicated on May 30, 1968. The arch is the tallest monument in the United States and a symbol of the city's role as the "Gateway to the West."

5. The 1973 tornado outbreak in Missouri occurred on May 30 and produced 30 tornadoes across the state. The outbreak caused extensive damage and killed three people. It is still one of the deadliest tornado outbreaks in Missouri history.