If what you say is true, then I don’t know what all the fuss about Obama’s citizenship is except people not liking him or his views.
There are people who don’t believe that he was born in the United States (some think Kenya, some think Indonesia and others say Canada) and under the rules in place in 1961 his 18 year old mother was three months too young to qualify him for Citizenship At Birth. She would have had to be 19 years old at the time of his birth if he was born abroad.
That’s a legitimate legal/constitutional argument.
There are a couple of different issues regarding Obama's citizenship status. The first is whether he was actually born inside the borders of the United States. This aspect of his citizenship was only a topic of discussion because of the general assumption/assertion that he was born in Kenya.
The law on this is quite clear. If he was not born inside the borders of the United States, he is not a US Citizen at all, so the speculation as to where he was born became somewhat important.
The Second issue with his citizenship status was whether or not the requirement of "natural born citizen" could be fulfilled by being just a "citizen." The consensus among the legal "experts" is that any sort of citizen is good enough to meet the requirement of "natural born citizen" as outlined in article 2 of the US constitution.
This claim is of course hogwash, and can be demonstrated to be a false assertion by referencing several past statements and events in history, not to mention that it doesn't even make sense logically.
But it doesn't really matter anymore because we are way through the looking glass of legal insanity. Our laws simply mean whatever the current crop of judges want them to mean. They have no solid meaning and have now become infinitely flexible.
Obama is not a "natural citizen" and there is reasonable possibility that he's not even a US Citizen of any sort at all.