Atlanta ( /ətˈlæntə/, stressed /ætˈlæntə/, locally /ætˈlænə/) is the capital and the most populous city in the U.S. state of Georgia with a 2010 population of 420,003. Atlanta is the cultural and economic center of the Atlanta metropolitan area, which is home to 5,268,860 people and is the ninth largest in the U.S. It is a major component of a growing southeastern megalopolis known as the Piedmont Atlantic Megaregion. Atlanta is the county seat of Fulton County, and a small portion of the city extends eastward into DeKalb County.
Atlanta began as a settlement located at the terminus of a railroad line, and it was incorporated in 1845. Today, the city is a major business city and the primary transportation hub of the Southeastern United States (via highway, railroad, and air), with Hartsfield–Jackson Atlanta International Airport being the world's busiest airport since 1998. The World Cities Study Group at Loughborough University rated Atlanta as an "alpha(-) world city." With a gross domestic product of US$270 billion, Atlanta's economy ranks 15th among world cities and sixth in the nation. The city is a center for services, finance, information technology, government, and higher education. Metro Atlanta contains the country's third largest concentration of Fortune 500 companies, and is the world headquarters of The Coca-Cola Company, Turner Broadcasting, The Home Depot, AT&T Mobility, UPS, and Delta Air Lines. As of 2010, Atlanta is the seventh most visited city in the United States, with over 35 million visitors per year.
The term black people is used in some socially-based systems of racial classification for humans of a dark-skinned phenotype, relative to other racial groups represented in a particular social context. Different societies apply different criteria regarding who is classified as "black", and often social variables such as class and socio-economic status also play a role, so that relatively dark-skinned people can be classified as white if they fulfill other social criteria of "whiteness" and relatively light-skinned people can be classified as black if they fulfill the social criteria for "blackness" in a particular setting.
As a biological phenotype being "black" is often associated with the very dark skin colors of some people who are classified as "black". But, particularly in the United States, the racial or ethnic classification also refers to people with all possible kinds of skin pigmentation from the darkest through to the very lightest skin colors, including albinos, if they are believed by others to have African ancestry, or to exhibit cultural traits associated with being "African-American". As a result, in the United States the term "black people" is not an indicator of skin color but of socially based racial classification.