Originally Posted by
BelgianWaffle
How does the CBP verify that someone is a genuine US citizen? (not a Canadian posing as one)
I don't think they verify citizenship of each passenger who claims to be a US citizen. Why would a Canadian pose as a US citizen? Just for fun? It all boils down to risk vs. reward. Those who speak and act like Americans most likely already can visit USA legally. Those who want to immigrate illegally probably can't pose as Americans no matter how hard they try.