It is often said that managing an airport is like being mayor of a city. Similar to a city, an airport is comprised of a huge variety of facilities, systems, users, workers, rules, and regulations. Also, just as cities thrive on trade and commerce with other cities, airports are successful in part by their ability to successfully be the location where passengers and cargo travel to and from other airports. Furthermore, just as cities find their place as part of their county’s, state’s, and country’s economy, airports, too, must operate successfully as part of the nation’s system of airports. In this chapter, the airport system in the United States will be described in a number of ways. First, the national airport system, as a whole, will be described. Next, the various facilities that make up the airport system will be described. Finally, the various rules and regulations that govern the airport system will be described.