When Is It Necessary To Stamp The Passport? US citizen passports are generally not stamped by CBP. However, officers may even stamp a US passport at the individual's request or at their discretion.
People Also Ask
If everything is running like clockwork, however, you have absolutely nothing to lose by asking politely for an official stamp. More often than not, the officer will be happy to give you one and you'll have an extra memory to take away from your travels. It can even work in places where there isn't immigration.
It's important to remember to hand in your paper I-94 when leaving the United States, since that's how the U.S. government will track your departure and know that you left the country before your visa expired. You'll use information from your I-94 travel record for many immigration purposes.