The concept of dual nationality means that a person is a citizen of two countries at the same time. Each country has its own citizenship laws based on its own policy. Persons may have dual nationality by automatic operation of different laws rather than by choice. For example, a child born in a foreign country to U.S. citizen parents may be both a U.S. citizen and a citizen of the country of birth. For more information on dual nationality please visit the Consular Affairs website.
At the time the U.S. Constitution and its natural born citizen clause was adopted, there was no such thing as dual citizenship. You had to give your allegiance to one sovereign. Britain and the British Empire went further by demanding allegiance to the British sovereign for a person’s entre life, with no recognition of any right to adopt another citizenship. A person born in Canada was born with Canadian citizenship. The U.S. Government does not officially recognize a right to dual citizenship or multiple citizenship. Instead, the Supreme court of the United States has compelled the Executive branch of the U.S. Government to not take away the citizenship of persons exercising foreign citizenship in addition to U.S. citizenship, except in those statutory circumstances where a person’s foreign citizenship is excluded. U.S. citizenship acquired at birth in a foreign sovereignty without two U.S. citizen parents does not qualify as natural born U.S. citizenship.