Final answer:
An application for a U.S. passport can be obtained at the post office, which is necessary for international travel by federal law established in 1952.
Step-by-step explanation:
You can get an application for your passport issued by the federal government at the post office. Passports are critical for international travel as they serve as official government identification for U.S. citizens leaving or entering the country. This requirement was put in place beginning with the Immigration and Nationality Act of 1952. Every citizen is entitled to due process, including a hearing if the issuance of a passport is denied. This right was affirmed by the Supreme Court in Kent v. Dulles.