There was never any doubt about Citizenship, but there has always been doubt as to NBC status. I was in the Military 58 years ago and this came up in discussions frequently, I never new anyone that doubted that if we had children overseas, they would not be eligible to be President.
Think of all the Children our men left in various outposts.
Right but of course there you had only one parent as a U.S. citizen so not a "natural born" citizen.