1. The Louisiana Purchase was finalized on September 12, 1803. This was a historic moment for the state and the nation as a whole, as it effectively doubled the size of the United States and opened up new opportunities for exploration and expansion.

2. On September 12, 1865, Civil War General James Longstreet joined the Republican Party in New Orleans. This was a controversial move at the time, as Longstreet had been a prominent Confederate general during the war.

3. Jazz pioneer Louis Armstrong was born in New Orleans on September 12, 1901. Armstrong went on to become one of the most influential musicians of the 20th century, and his legacy remains an important part of Louisiana's cultural heritage.

4. The town of Leeville, Louisiana was completely destroyed by Hurricane Audrey on September 12, 1957. The storm caused extensive damage and loss of life throughout the region, and remains one of the deadliest hurricanes to ever strike the United States.

5. September 12, 2005 marked the one-year anniversary of Hurricane Katrina, which devastated the Gulf Coast region and caused widespread destruction in Louisiana. The state has since undergone a long and difficult recovery process, but has shown resilience and strength in the face of adversity.