1. On September 20, 1803, the Louisiana Purchase was officially signed, marking the transfer of the territory from France to the United States. This event doubled the size of the United States and helped to shape the country's expansion westward.

2. In 1973, on September 20, Bill Conti composed the iconic theme song for the boxing film Rocky. Conti, who was born and raised in Louisiana, went on to become a highly successful composer known for his work on other films such as The Karate Kid and The Right Stuff.

3. On September 20, 1963, the New Orleans Saints football team was officially announced as the 27th franchise in the National Football League. The team played its first game in 1967 and has since become a beloved institution in Louisiana, with fans known for their enthusiastic support.

4. In 1862, on September 20, Confederate General Braxton Bragg led his forces against Union forces commanded by General Don Carlos Buell in the Battle of Mumfordville. The Confederates were ultimately successful in capturing the Union garrison, though the victory was short-lived as the Union forces would regroup and continue their advance further south.

5. On September 20, 2005, Hurricane Rita made landfall near the Louisiana-Texas border, causing widespread destruction and claiming the lives of over 100 people. The storm was one of the most powerful hurricanes on record, with sustained winds of up to 180 miles per hour at its peak. It remains one of the most significant weather events in Louisiana's recent history.