1. In 1902, the town of Gary, Indiana was incorporated. Named after Elbert Henry Gary, a successful lawyer and chairman of US Steel Corporation, the town quickly became known for its steel manufacturing industry.

2. On May 31, 1928, the Indianapolis 500 automobile race was held for the 16th time. The winner that day was Louis Meyer, who would go on to win the race two more times in his career.

3. The construction of the Hoosier Dome, now known as the RCA Dome, was completed on May 31, 1984. Located in downtown Indianapolis, the dome served as the home stadium for the NFL team the Indianapolis Colts until 2008.

4. May 31, 1969 marks the start of the 1969 EF-4 Cincinnati outbreak. This series of 10 tornadoes caused extensive damage throughout the Midwest, including in Indiana, and resulted in 4 fatalities.

5. In 1865, the state of Indiana ratified the 13th Amendment to the United States Constitution, which officially abolished slavery in the country. Indiana was the second state in the Union to ratify the amendment, after Illinois.