Baker v. Selden, 101 U.S. 99 (1879), was a leading Supreme Court of the United States copyright case cited to explain the idea-expression dichotomy. The court held that a book did not give an author the right to exclude others from practicing what was described in the book, only right to exclude reproduction of the material in the book. Exclusive rights to an "useful art" described in a book was only available by patent.