Arrival/Departure Records Are Available Online
I-94 form Arrival/Departure record is the main form that has been used for decades to track admission and departure of the non US residents. Recently, however, Department of Homeland Security substituted the paper version with the electronic record.
The I-94 form is crucial to prove inspection and admission of a non- resident who seeks adjustment of status or most of other Immigration benefits: for example, a request to change/extend status.
So far, to restore the records a person could have applied to get a new I-94 card by submitting form I-102 with the USCIS. Also, a Freedom of Information Act Request could have been filed with the CBP. A FOIA request would be helpful when a person who is seeking to restore the arrival/departure record is not sure as to the dates of the arrival. The problem is FOIA request is that it takes minimum of 9 months to get a response to.
Now, the CBP websites offers to get the records instantaneously for the past 5 years. It also warns applicants that it will retain data they enter through the website for 3 months for audit purposes. Simple checks of the system, however, so far rendered no results: the system gives response that the records are not found. It means that it will probably take some time for the system to work properly.
It seems that the paper form of the record is still a more reliable one. All non-citizens are encouraged to keep their arrival/departures records.
The CBP website providing the I-94 record can found here: I-94 Arrival Departure records.