Atlanta is the capital and most populous city of the state of Georgia in the United States. It is the county seat of Fulton County, although a portion of the city (the 1909 annexation) extends into DeKalb County. According to the July 2005 census estimate, the city has a population of 470,688 and a metropolitan population of 4,917,717, making it the 35th largest city and 9th largest metropolitan area in the United States. As of July 1, 2005, Atlanta's combined statistical area (CSA) is estimated to have a population of 5,249,121.

The city is encompassed by Interstate 285, locally known as the Perimeter, which has come to delineate the interior of the city from the surrounding suburbs. As a result, terms such as ITP (Inside The Perimeter) and OTP (Outside The Perimeter) have arisen to describe area neighborhoods, residents, and businesses. The Perimeter plays a social and geographical role similar to that of Interstate 495 (Capital Beltway) around Washington, DC.

Post World War II, Atlanta has become considered the Gateway to the New South or Capital of the New South in the media [citation needed]. Today, Atlanta is one of the most important, if not the most important, economic centers in the Southern United States, and is considered a Gamma world city. With a rich history and a large population, Atlanta has long served as a major cultural and economic center.

The city of Atlanta has undergone several major incarnations. Originally a 'railroad boomtown' that became a focal point of the Civil War, Atlanta was largely destroyed in 1864 by Union general William T. Sherman but emerged from the ashes (hence the city's symbol, the Phoenix) to become the postwar capital of Georgia (1868) and a symbol of the 'New South.' While Atlanta's business leaders focused on making Atlanta a Southern version of New York and Chicago, the city served as a dean of Southern culture, and was the setting for much of Margaret Mitchell's novel, Gone With the Wind. During the Civil Rights movement, Atlanta stood apart from other Southern cities (which supported segregation) and became known as the 'City Too Busy to Hate.' The city's progressive Civil Rights record made it increasingly popular with blacks, and the black population formed a majority by 1972. This has led to African-Americans becoming the dominant political force in the city. Since 1974, mayors of Atlanta have been African American, in addition to the majority of fire chiefs, police chiefs, and other high-profile government officials. 'White flight' from the city in the 1970's and 1980's(the city's population dropped by more than 100,000 from 1970 to 1990) has been reversed, however, since 1990, and the black majority has dropped from 69% in 1980 to 61% in 2000. The city is becoming increasingly diverse although it remains politically black, with a majority-white business class.

Common colloquialisms for the city include A Town, The A-T-L (derived from its IATA airport code), Hotlanta, and The A. It is common for those unfamiliar with Atlanta to associate it with Hartsfield-Jackson Atlanta International Airport. The international airport is the busiest in the world in terms of passenger traffic, due, in part, to it being the major airline hub of Delta Air Lines.