1. In 1803, the United States and France signed the Louisiana Purchase, which included the vast territory of Louisiana. This historic event paved the way for the expansion of the United States and had a profound impact on the history of Louisiana and the rest of the nation.

2. In 1815, the Battle of New Orleans was fought on February 25, marking the final major battle of the War of 1812. Led by General Andrew Jackson, the American forces defeated the British army in a decisive victory that became an important symbol of American strength and resilience.

3. In 1861, Louisiana seceded from the Union and joined the Confederacy, becoming a key battleground in the Civil War. The state's strategic location and valuable resources made it a target for both Union and Confederate forces, and many important battles were fought on Louisiana soil.

4. In 1892, the people of New Orleans celebrated the first Mardi Gras parade to be held at night. This tradition, which had been established in the city in the early 1800s, became even more colorful and festive with the addition of electric lighting and elaborate floats.

5. In 2006, Hurricane Katrina struck Louisiana, causing massive devastation and loss of life across the state. The storm, which made landfall on August 29 but continued to cause flooding and destruction for weeks afterward, was one of the deadliest and most destructive hurricanes in U.S. history. The recovery and rebuilding efforts in Louisiana have been ongoing, with many challenges still remaining.