“No, at age 4 he would have entered the country on his mother’s passport.”
Not necessarily. My grandson was a natural born American citizen, born in London. He came to this country at age 2 under his American Passport. His father, a natural born American citizen, took him through the American Citizen customs line in Houston, Texas. His mother, a British citizen, had to go through the out of country customs line.
That grandson graduates from high school next year in England and will come to this country as a natural born American Citizen to attend either MIT or Harvard. Those contacts are already made.
Coming from Canada into the US was a little different back in the 70’s. In general, a passport wasn’t even needed to pass between the two countries. It has only been in the last 10-15 years that a passport has been required to go between Canada and the US for citizens of either country. And I think I read that Ted got his passport when he went on an international trip when he was in high school.