Yes, it is the case. In 35 U.S.C. 103: >(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section

Yes, it is the case. In 35 U.S.C. 103: >(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102 of this title, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negatived by the manner in which the invention was made.