Atlanta is the capital of and the most populous city in the U.S. state of Georgia, with an estimated 2013 population of 447,841. Atlanta is the cultural and economic center of the Atlanta metropolitan area, home to 5,522,942 people and the ninth largest metropolitan area in the United States. Atlanta is the county seat of Fulton County, and a small portion of the city extends eastward into DeKalb County.Atlanta was established in 1837 at the intersection of two railroad lines, and the city rose from the ashes of the Civil War to become a national center of commerce. In the decades following the Civil Rights Movement, during which the city earned a reputation as "too busy to hate" for the progressive views of its citizens and leaders, Atlanta attained international prominence. Atlanta is 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.Atlanta is considered an "alpha-" or "world city", and with a gross domestic product of $270 billion, Atlanta's economy ranks 15th among world cities and sixth in the nation. Although Atlanta's economy is considered diverse, dominant sectors include logistics, professional and business services, media operations, and information technology. Topographically, Atlanta is marked by rolling hills and dense tree coverage. Revitalization of Atlanta's neighborhoods, initially spurred by the 1996 Olympics, has intensified in the 21st century, altering the city's demographics, politics, and culture.