1. The Louisiana Purchase Treaty was ratified on May 13, 1803. The treaty, which was signed on April 30, 1803, between the United States and France, transferred the Louisiana Territory from France to the United States for $15 million.

2. The New Orleans riot of 1866 broke out on May 13, 1866. The riot, which lasted for three days, was sparked by tensions between white supremacists and newly freed slaves. It resulted in a number of deaths and injuries, and was a major point in the Reconstruction Era in Louisiana.

3. On May 13, 1918, the first air mail flight in Louisiana took off from New Orleans. The flight was part of a nationwide effort to establish the first regularly scheduled air mail service. The pilot, Lt. George L. Boyle, flew a route that went from New Orleans to Memphis, Tennessee.

4. The Louisiana State Capitol building was dedicated on May 13, 1932. The building, located in Baton Rouge, is the tallest capitol building in the United States at 450 feet tall. It was designed by architect Huey Long, who was also the governor of Louisiana at the time.

5. On May 13, 1997, the first Jazz Fest after Hurricane Katrina took place in New Orleans. The festival, which had been held annually since 1970, was cancelled in 2006 due to Hurricane Katrina, but returned the following year with performances by Stevie Wonder, Bob Dylan, and Lionel Richie, among others.