1. In 1803, the Louisiana Purchase Treaty was signed, in which the United States bought over 800,000 square miles of land from France, including Louisiana. This treaty was signed on April 17 and marked a significant moment in the history of Louisiana and the United States.

2. On April 17, 1862, the Battle of Fort Pillow took place in Tennessee, which had significant implications for the Louisiana troops who fought in the battle. The Louisiana Tigers regiment, made up of volunteers from Louisiana, fought for the Confederacy in this battle and suffered heavy casualties.

3. In 1928, Huey P. Long, a prominent political figure in Louisiana, was elected governor of the state. Long was known for his populist views and used his power to implement several state-funded programs that helped poor Louisianans. Long's election on April 17 marked the beginning of his political career and legacy in Louisiana.

4. In 1945, the USS Louisiana was commissioned, becoming the third battleship in the United States Navy to be named after the state. The USS Louisiana served during World War II, the Korean War, and Operation Desert Storm. Its commission on April 17 was a significant moment for the Navy and Louisiana's military history.

5. On April 17, 2019, a devastating fire broke out at the Notre-Dame Cathedral in Paris, France. This event had deep emotional and cultural ties with Louisiana, as many of the state's communities share a French heritage and connection to the cathedral. The fire sparked a global conversation about the importance and fragility of cultural landmarks and historic monuments.