Ronald Reagan Washington National Airport, referred to colloquially as Reagan Airport, Reagan National, and National Airport, is a civil airport located in Crystal City, Virginia, in Arlington County, Virginia, 5 miles (8.0 km) from Washington, D.C. It is the closest airport to Washington, D.C., the nation's capital, the 23rd-busiest airport in the nation, and the busiest airport in both the Washington metropolitan area and the Washington–Baltimore combined statistical area.

United States border preclearance is the United States Department of Homeland Security's (DHS) practice of operating prescreening border control facilities at airports and other ports of departure located outside of the United States pursuant to agreements between the United States and host countries. Travelers are subject to immigration and customs inspections by Customs and Border Protection (CBP) officers before boarding their transportation onward to the United States. Preclearance applies to all passengers regardless of their nationality or purpose of travel. Upon arrival, precleared passengers arrive in the United States as domestic travelers, but may still be subject to re-inspection at the discretion of CBP. This process is intended to streamline border procedures, reduce congestion at American ports of entry, and facilitate travel into airports that otherwise lack immigration and customs processing facilities for commercial flights.