- Apr 4 Congress decides on the US flag: 13 red & white stripes & 20 stars
Victory in Battle
Apr 5 In the Battle of Maipú, Chile's independence movement - led by Bernardo O'Higgins and José de San Martín - win a decisive victory over Spain, leaving 2,000 Spaniards and 1,000 Chilean patriots dead.
Victory in Battle
Apr 7 General Andrew Jackson conquers Spanish Fort San Marcos (St Marks), in Spanish Florida during his pursuit of the Native American Seminole Tribe, in what would become known as the First Seminole War
- Apr 21 Franz Grillparzer's "Sappho" premieres in Vienna
Historic Event
Apr 28 US President James Monroe proclaims naval disarmament on Great Lakes and Lake Champlain