Thank you !
Thank you very much for your help!!! I really appreciated.
I contacted Customer Service Center for U.S. Customs and Border Protection with the same question and they answered me with the following:
"This will not be a problem since CBP has a record of your travel to and from the US. The officer did not stamp the passport because you already have a permanent resident card. Here is a link that will explain how you can get a copy of that record for your citizenship application. I hope this information helps.
Answer Title: How can I get a record of my travel in and out of the United States?
CBP only has complete records of the entry and exit of persons arriving and departing by air or sea. If you are a legal permanent resident and crossed at a land border, it is unlikely that we would have a record of your travels. Also CBP's records only go back to 1982, even for air travel.
Information about someone's movements is protected by the Privacy Act and may only be released to the subject of the records or their designated representative.
Please print out the attached sheet below, fill it out and send it to:
U.S. Customs and Border Protection
1300 Pennsylvania Ave., NW,
Attn: Mint Annex Building, FOIA Division
Washington, D.C. 20229
Be sure to include in your request the approximate time frame of your entry and exits, your full name and date of birth, passport number and alien number. You must sign the request for information in ink. Unsigned requests will be rejected.
The process for researching our records is time consuming and as a result, there may be a charge for this service. If there is a charge, we will notify you of the amount in advance.
It takes some time to process these requests and depending on the backlog it could take significantly longer. There is no way to expedite the request, in order to avoid additional delays, make sure that your original request has all the requested information."