What if I don’t remember where I entered the U.S.? Where can I find this information?

Locate the three-letter code

According to the USCIS, when you are entering the U.S. you must enter through a port of entry. The name of the city where the port of entry is located is abbreviated by a three-letter code. For example, if you entered through Houston, Texas the port of entry will be abbreviated as HOU, Atlanta = ATL, etc. You can usually find this information located on your I-94 or your passport entry stamp. CITATION: http://www.uscis.gov/tools/glossary/port-entry http://www.state.gov/documents/organization/88037.pdf