For someone how has never travelled to the United States before, a likely question to arise in their mind would be "What happens at the Port of Entry when I arrive?"

Foreign travelers to the United States, will arrive initially at a so-called "port of entry" (POE). This POE can be an airport, a land border crossing, or a seaport. Generally speaking you are asking the border officer (a member of the U.S. Customs and Border Protection agency, or CBP) for permission to enter the United States, for a specific reason, purpose and duration.

Once travelers present their passport and other required documents at the port of entry, CBP officers determine who to admit and how long each traveler may stay. CBP officers first encounter travelers at primary inspection where they ask travelers questions to determine, among other things, their identity and nationality. The officers also review passports, visas, and other documents, compare the fingerprint records and namecheck databases for recent derogatory information, ask questions about the travelers' general qualifications for the visas they have, review the Form I-94 Arrival and Departure Record (or, for Visa Waiver travelers, I-94W).

Based on this information, CBP officers determine if the traveler is eligible to enter the United States. Once the inspector stamps and dates the I-94 forms and the admission stamp in the travelers' passports and the traveler passes through the inspection process, the travelers are admitted to the United States.

If additional time is needed to review a traveler's eligibility, CBP can refer a traveler to secondary inspection for a more extensive review. Travelers referred to secondary inspection are not considered to be admitted to the United States.

What happens in secondary inspection?

In secondary inspection, travelers are asked more detailed questions about their travel and are asked to produce additional identification and other documentation in order to determine their actual identity and purpose of visit. The traveler and their belongings may also be searched and the traveler may be subjected to a full set of fingerprints.

Other federal agencies may interview the traveler to determine compliance with a wide variety of federal laws and regulations. The traveler may also be held in secondary for a reasonable amount of time for government personnel from federal agencies to arrive at the port of entry for an interview.

Any traveler, even someone presenting a U.S passport, may be sent into secondary if the CBP officer has any reservations about admitting a traveler into the United States or the possibility of the traveler smuggling contraband or violating any other customs or immigration regulations, or federal law in general.