Atlanta is the capital and most populous city of the U.S. state of Georgia. It is the county seat of Fulton County and extends into neighboring DeKalb County. With a population of 498,715 at the 2020 census and an estimated 520,070 in 2024, Atlanta is the eighth-most populous city in the Southeast and the 36th-most populous city in the United States. Atlanta is classified as a Beta+ global city. The Atlanta metropolitan area has an estimated population of over 6.4 million and is the eighth-largest metropolitan area in the United States. Situated among the foothills of the Appalachian Mountains at an elevation of just over 1,000 feet (300 m) above sea level, Atlanta features a unique topography that includes rolling hills, lush greenery, and the densest urban tree coverage of any major city in the United States.
Atlanta was originally founded as the terminus of a major state-sponsored railroad, but soon became the convergence point for several railroad lines, spurring its rapid growth. The largest of these was the Western and Atlantic Railroad, from which the name "Atlanta" is derived, reflecting the city's growing reputation as a major transportation hub. During the American Civil War, the city served a strategically important role for the Confederacy until it was captured in 1864. Atlanta was almost entirely burned to the ground during General William T. Sherman's March to the Sea. However, it rebounded dramatically in the post-war period and quickly became a national industrial center and the unofficial capital of the "New South". After World War II, Atlanta emerged as a manufacturing and technology hub. During the 1950s and 1960s, it became a major organizing center of the American civil rights movement, with Martin Luther King Jr., Ralph Abernathy, and many other locals serving as prominent leaders. In the modern era, Atlanta has remained a major transportation center, with Hartsfield-Jackson International Airport becoming the world's busiest airport by passenger traffic in 1998. It has maintained this position every year since, except in 2020, with an estimated 93.7 million passengers in 2022.