Top 50 major Airports In America by population Busiest International U.S. Airports by total commercial Aircraft   1. Hartsfield-Jackson Atlanta International Airport (ATL) As the busiest Airport in the world, Atlanta’s Hartsfield-Jackson International Airport (ATL) is known for moving huge numbers of passengers efficiently and smoothly every day. It’s the main hub for Delta Air Lines, which means that a large number of Delta’s Flights in the U.S. and internationally pass through Atlanta. The Airport’s unique design has a central "spine" with seven concourses lined up next to each other, all linked by the underground "Plane Train." This train is actually the most-used automated people mover in the world, helping millions of people get to their gates quickly. Even though the Airport is massive, ATL stands out for more than just its size. It has a vibrant food scene, highlighted by "One Flew South," a restaurant that’s been called one of the best Airport re...