There’s been a little editing back-and-forth over at Wikipedia about what is put in the “nationality” field for the various Peanuts kids.
Thing is, in what is considered absolute canon — the strip itself — this question is never actually answered. Most of the time that you see the word “citizen” in the strip, it is followed by the name “Kane”. It is easy to assume that the kids are all American, they certainly seem to live in the US, but we have no proof that, say, Lucy didn’t move her from Toronto with her famiy when she was a baby.
Of course, with her desire to become President, Lucy might not be aware of the “natural born citizen” clause in the Constitution. Charlie Brown’s father also believe him to be eligible for the job, but ignorance on the requirements for the presidency run rampant.
There is, in fact, just one character in Peanuts who gets refered to as an “American”… and that’s Snoopy, who is probably actually ineligible for citizenship owing to the fact that he is a dog, and that, in his own thoughts, tomorrow he’ll “probably still be a dog”.
