The U.S. received the N as its nationality designator under the International Air Navigation Convention, held in 1919. The Convention prescribed an aircraft-marking scheme of a single letter indicating nationality followed by a hyphen and four identity letters (for example, G-REMS).

The "N" seen at the beginning of registration numbers on the side of airplanes (e.g., N12345) is the International Civil Aviation Organization (ICAO) nationality prefix for the United States. Every country has its own unique prefix: "G" for the United Kingdom, "C" for Canada, "F" for France, and so on. The letter "N" was originally assigned to the U.S. during the International Air Navigation Convention in 1919. Today, these are commonly referred to as "N-Numbers." Federal law requires that all U.S.-registered aircraft display this mark clearly on the fuselage or tail. The characters following the "N" provide a unique identifier for that specific airframe, similar to a car's license plate. Interestingly, "N" doesn't actually stand for "North America" or "National"—it was simply a letter assigned in an alphabetical block. Since 1948, the FAA has managed these registrations, ensuring that every private Cessna and commercial Boeing flying under a U.S. flag can be tracked and identified globally.