Atlanta, is the capital and most populous city in the U.S. state of Georgia. According to the 2010 census, Atlanta's population is 420,003.The Atlanta metropolitan area, with more than 5.4 million people, is the third largest in the Southeastern United States and the ninth largest in the country. The Atlanta Combined Statistical Area, a larger trade area, has a population approaching six million and is the largest in the Southeast. Like many urban areas in the Sun Belt, the Atlanta region has seen increasing growth since the 1970s, and it added about 1.1 million residents between 2000 and 2008.
Atlanta is considered to be a top business city and is a primary transportation hub of the Southeastern United States—via highway, railroad, and air. Metro Atlanta contains the world headquarters of corporations such as The Coca-Cola Company, The Home Depot, AT&T Mobility, UPS, Delta Air Lines, and Turner Broadcasting. Atlanta has the country's fourth-largest concentration of Fortune 500 companies, and more than 75 percent of Fortune 1000 companies have business operations in the metropolitan area, helping Atlanta realize a gross metropolitan product of US$270 billion, accounting for more than two-thirds of Georgia's economy. Hartsfield–Jackson Atlanta International Airport has been the world's busiest airport since 1998.
Atlanta is the county seat of Fulton County and the location of the seat of government of the state of Georgia. A small portion of the city of Atlanta corporate limits extends eastwards into DeKalb County. Residents of Atlanta and its surroundings are known as "Atlantans"
According to the United States Census Bureau, the city has a total area of 132.4 square miles (342.9 km2). 131.7 square miles (341.1 km2) of it is land and 0.7 square miles (1.8 km2) of it is water. The total area is 0.54% water. At about 1,050 feet (320 m) above mean sea level the airport is at 1,010 feet (308 m), Atlanta sits atop a ridge south of the Chattahoochee River.
The Eastern Continental Divide line enters Atlanta from the south, proceeding to the downtown area. From downtown, the divide line runs eastward along DeKalb Avenue and the CSX rail lines through Decatur.Rainwater that falls on the south and east side runs eventually into the Atlantic Ocean, while rainwater on the north and west side of the divide runs into the Gulf of Mexico via the Chattahoochee River. That river is part of the ACF River Basin, and from which Atlanta and many of its neighbors draw most of their water. Being at the far northwestern edge of the city, much of the river's natural habitat is still preserved, in part by the Chattahoochee River National Recreation Area. Downstream however, excessive water use during droughts and pollution during floods has been a source of contention and legal battles with neighboring states Alabama and Florida.