1. In 1803, the Louisiana Purchase Treaty was signed in Paris, France, which officially transferred ownership of the Louisiana Territory from France to the United States. This purchase substantially increased the size of the United States, and had significant historical and cultural impacts on Louisiana.

2. On August 3, 1864, the Battle of Mobile Bay occurred during the American Civil War. Union Admiral David Farragut famously declared "Damn the torpedoes!" as his fleet navigated through a minefield to capture the Confederate-held port of Mobile, Alabama. This victory helped seal the fate of the Confederacy and ultimately led to the end of the Civil War.

3. The Louisiana State Capitol building in Baton Rouge, one of the most recognizable landmarks in the state, was officially dedicated on August 3, 1932. Designed by architect Huey Long, the striking Art Deco building stands at 450 feet tall and is the tallest capitol building in the United States.

4. On August 3, 1958, the first class of African American students was enrolled in Louisiana State University (LSU), marking a significant milestone in the struggle for civil rights in the state. Despite significant challenges, these students paved the way for future generations of black students to attend LSU and other institutions of higher education.

5. Finally, August 3 is celebrated as "Watermelon Day" in Louisiana, a tribute to the beloved fruit that thrives in the state's warm climate. Louisiana is known for producing especially sweet and juicy watermelons, which are a staple of summer picnics and barbecues across the region.