A city of southeast Louisiana between the Mississippi River and Lake Pontchartrain. Founded in 1718, it became the capital of a French colony in 1722 and passed to the United States as part of the Louisiana Purchase of 1803. The city is known for its annual Mardi Gras celebrations and as the birthplace of jazz music. In 2005, New Orleans was devastated by Hurricane Katrina, which caused breaches in the protective levee system that resulted in widespread flooding and the evacuation of much of the city.