1. Kentucky became the 15th state of the United States on June 1, 1792. On May 15, 1792, the Kentucky Convention adopted the state's first constitution, paving the way for statehood.

2. On May 15, 1862, the Battle of Perryville took place in Boyle County, Kentucky during the American Civil War. This battle was one of the most significant conflicts in the Western Theater and resulted in approximately 7,600 casualties.

3. In 1910, the first Kentucky Derby was held at Churchill Downs in Louisville, Kentucky on May 15th. The race was won by a horse called "Donerail" who had the longest odds in the history of the race at 91-to-1.

4. On May 15, 1938, Kentucky's Mammoth Cave National Park was dedicated. This park is home to the world's longest known cave system, with over 400 miles of explored cave passageways.

5. In 2004, the Kentucky Bourbon Trail was established on May 15th to promote tourism and celebrate the state's historic bourbon industry. The trail features nine distilleries in Kentucky that produce some of the world's best-known bourbons, including Jim Beam and Maker's Mark.