Entering the USA: What Happens at the Airport?
When a foreign fiancée arrives at the airport (i.e., the port of entry), he or she can expect the following:
The Customs and Border Protection (CBP) Officer must determine why you are coming to the United States, what documents you may require, if you have those documents, and how long you should be allowed to initially stay in the United States. These determinations usually take less than one minute to make. If you are allowed to proceed, the officer will stamp your passport and customs declaration form and issue a completed Form I-94 to you. A completed form I-94 will show what immigration classification you were given and how long you are allowed to stay.
Also, if you are an alien, CBP Officers may decide that you should not be permitted to enter the United States. There are many reasons why this might happen (see INA § 212(a)). You will either be placed in detention, or temporarily held until return flight arrangements can be made. If you have a visa, it may be cancelled. In certain instances, Officer(s) may not be able to decide if you should be allowed into the United States. In this case, your inspection may be deferred (postponed), and you will be instructed to go to another office located near your intended destination in the United States for further processing.