Most countries in North and South America have unconditional birthright citizenship for persons born in the country.

I take it you are not British? The British Empire had birthright citizenship, and up until 1948 (except for Ireland) citizens of all Commonwealth countries were simply British subjects.

Afterward it was possible to be, for example, a Canadian citizen, but it was still the case that "Prior to the [the British Nationality Act 1981] coming into force, any person born in the United Kingdom or a colony (with limited exceptions such as children of diplomats and enemy aliens) was entitled to [Citizenship of the United Kingdom and Colonies] status" - https://en.wikipedia.org/wiki/British_Nationality_Act_1981