I do remember, back when he was first elected to the IL Senate, that there were news stories about the unlikely event and that he was from Kenya. A complete review of local IL papers and news in that time might turn up what I remember..I have not been able to find it. This was long before his national fame.
His time in the Illiois senate was just a stepping stone, he was always "present" and nothing more.
Here ya go:
http://web.archive.org/web/20040627142700/eastandard.net/headlines/news26060403.htm
obama was in a number of papers being announced as the first african born (Kenya) senator elected to the U.S. senate. HE did not claim to be a Natural born citizen.
He did not become “American born” until he ran for the office of the President.