How do you say 'I'm from the US' in Spanish?

Nací en los Estados Unidos. (I was born in the U.S.)

Nací en las Américas. (I was born in the Americas -- meaning the continents of North, Central (I think this is technically part of N. A.), and South America.)

Nací en América del Norte (I was born in North America -- Canada, USA, Mexico...etc)

Nací en América del Sur (I was born in South America -- Brazil, Argentina, Chile... etc)