That does not make him a Natural Born Citizen. To be considered a Natural Born Citizen, both parents must be US citizens when a child is born to pass Natural Born Citizen status to the child. This is why Obama is not eligible. His father was a British Citizen when he born, Barack Obama is not a Natural Born Citizen of the US for that reason. By British Natural Law, he received the citizenship of his father, regardless of where he was born, forever preventing him from Natural Born US Citizenship status.