|In 1920, a conference of the League of Nations (precursor to the United Nations) recommended that all passports should be issued in French and one other language, depending on the country. French was chosen as the primary passport language since it was traditionally “the language of diplomacy.” Many passports are still issued in French.|
After the 1920 League of Nations meeting, US passports were issued in English and French. Spanish was added in the late 1990s, in recognition of Spanish-speaking Puerto Rico.
The International Civil Aviation Organization (ICAO) of the United Nations issues passport standards which are treated as recommendations to national governments. Currently, ICAO recommends that passports be issued in English and French, or in the national language of the issuing country and in either English or French. Many European countries use their national language, along with English and French.