That depends on where you are crossing the border. In general you would have to refer to the U.S. Customs and Border Protection (CBP). You can get more information from their website at the attached related link.
The phone number of the American Canyon is: 707-644-1136.
The phone number of the American Falls District is: 208-226-2335.
The phone number of the American Legion is: 608-745-1090.
305-597-8866 only of Miami dolphin mall
The phone number of the African American Library is: 832-393-1440.
The phone number of the American Poetry Museum is: 202-249-0253.
The phone number of the American Fork City Library is: 801-763-3070.
The phone number of the American Antiquarian Society is: 508-755-5221.
The phone number of the American Rose Society is: 610-372-1605.
The phone number of the Swedish-American Historical is: 773-583-5722.
The phone number of the Museum For Hmong American is: 715-848-1970.
The phone number of the American Heritage Center is: 307-766-4114.