In most cases if you have one US parent, then you would probably be considered a US Citizen Born Abroad. You are suppose to document this with the local US Embassy. Then they issue you a "Report of a child born to a US Citizen Abroad" with the seal of the embassy. It is a federal form and filed with the Department of State.
I was born in Africa, near Casablanca, Marocco.
A person who immigrated or married a US Citizen overseas would have a Naturalization Certificate after living in the USA after 5-10 years. My wife is korean and she had to have a Visa to enter the USA Legally.