Not the text of the books themselves, no, but the autobiographical blurb that he submitted to his publisher, which was included on early editions of his first book stated that he was born in Kenya.
He also claimed that in interviews with the local media when he was first running for state office.
Tragically, the disaster that is our current President has set new standards for eligibility, but please note what the language of the Constitution says:
The term Natural born Citizen appears in our Constitution, in Article 1, Section 2, with these words, (quote) No person except a natural born citizen [born of two parents who were themselves citizens], or a citizen of the United States, at the time of the adoption of this Constitution, shall be eligible to the office of President; neither shall any person be eligible to that office who shall not have attained to the age of thirty five years, and been fourteen Years a resident within the United States. (unquote)
Please note that the founders made the distinction between “Natural Born Citizens” and “Citizens”.
If there were not a distinction in their minds, then there would have been to reason to list both “types” in their list of qualifications.