The Everglades are subtropical wetlands located in the southern portion of the U.S. state of Florida, comprising the southern half of a large watershed. The system begins near Orlando with the Kissimmee River, which discharges into the vast but shallow Lake Okeechobee. Water leaving the lake in the wet season forms a slow-moving river Everglades Airboat Tours60 miles wide and over 100 miles long, flowing southward across a limestone shelf to Florida Bay at the southern end of the state. The Everglades are shaped by water and fire, experiencing frequent flooding in the wet season and drought in the dry season. Also known as the "River of Grass" to describe the sawgrass marshes, part of a complex system of interdependent ecosystems that include cypress swamps, the estuarine mangrove forests of the Ten Thousand Islands, tropical hardwood hammocks, pine rockland, and the marine environment of Florida Bay.
Human habitation in the southern portion of the Florida peninsula dates to 15,000 years ago. Two major tribes eventually formed in and around Everglades ecosystems: the Calusa and the Tequesta. After coming into contact with the Spanish in the late 16th century, both tribes declined gradually during the following two centuries. The Seminoles, a tribe of Creeks who assimilated other peoples into their own, made their living in the Everglades region after being forced there by the U.S. military in the Seminole Wars of the 19th century.
Draining the Everglades was first suggested in 1848, but was not attempted until 1882. Canals were constructed throughout the first half of the 20th century, and spurred the South Florida economy, prompting land development. However, problems with canals and floods caused by hurricanes forced engineers to rethink their drainage plans. In 1947, Congress formed the Central and Southern Florida Flood Control Project, which built 1,400 miles of canals, levees, and water control devices. The South Florida metropolitan area grew substantially at this time and Everglades water was diverted to cities. Portions of the Everglades were transformed into farmland, where the primary crop was sugarcane.
Approximately 50 percent of the original Everglades has been turned into agricultural or urban areas. When the construction of a large airport was proposed 6 miles north of Everglades National Park, an environmental study predicted it would destroy the South Florida ecosystem. Restoring the Everglades then became a priority.