Originally Posted by
minhaoxue
It is true there is no Immigration when you depart the US but everything these days is done electronically. Airlines share APIS with CBP on arriving and departing passengers. Yes, Officers do look through the passport and through questioning, can determine past entries and length of stays.
Nowadays, both entry and exit appear to be tracked and will be available to CBP.
You can even look up your I-94 travel history here:
https://i94.cbp.dhs.gov/I94/request.html
It used to be entry only, but now both entry and exit are consistently showing up.