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 use of the letter "N" for U.S. aircraft registrations dates back to the 1919 International Air Navigation Convention. During this meeting, nations were assigned unique prefixes for their radio call signs and aircraft IDs. The U.S. was assigned "N" (Navy), "W" (Federal Government), and "K" (Commercial). The government ultimately chose "N" as the primary identifier because it was already widely used by the U.S. Navy for its radio transmissions and was seen as a clean, distinctive national marker. In the early days, "N" was followed by other letters (like "NC" for commercial or "NX" for experimental), but since 1950, all U.S.-registered aircraft simply use "N" followed by a unique alphanumeric string. This "N-Number" is a point of pride in American aviation, serving as a globally recognized symbol of the Federal Aviation Administration's (FAA) oversight and safety standards.