knucklehead:

What is really new is that the US now defacto recognizes dual citizenship. Historically, the UK and its dominions have always held once a brit always a brit. It caused no end of problems in the early days of the Republic. To American seaman the RN boarding party’s question of when and where were you born could have a major impact on your life. For someone born in Boston in 1781 it meant an immediate transfer from the US merchant service to the Royal Navy because you born a British subject and you would die that way.