1. Louisiana Purchase: On October 23, 1803, the Louisiana Purchase was finalized in New Orleans, Louisiana. This purchase involved the acquisition of over 800,000 square miles of land that belonged to France at the time, doubling the size of the United States.

2. Huey P. Long: On October 23, 1929, Huey P. Long became the youngest Governor of Louisiana at the age of 35. Long's tenure as a governor was marked by his ambitious social engineering programs, which helped the state's poor and working-class citizens.

3. Plessy v. Ferguson: On October 23, 1892, Homer Plessy was arrested for refusing to move from a "whites-only" train car in Louisiana, leading to the landmark Supreme Court case of Plessy v. Ferguson. The ruling in this case upheld the practice of racial segregation, allowing Jim Crow laws to endure for decades.

4. Devastating flood: On October 23, 1957, a devastating flood hit New Orleans, causing 22 deaths and over $100 million in damages. This flood was caused by heavy rains and the failure of the city's levee system.

5. Rise of Cajun music: On October 23, 1976, the first Festivals Acadiens was held in Lafayette, Louisiana. This festival focused on celebrating the rich cultural heritage of Cajun music, food, and traditions, and has since become an annual event that draws thousands of visitors from around the world.