The United States patent system was established by the first U.S. Congress in 1790 under a specific grant of authority in the U.S. Constitution, specifically Article I, Section 8. That section states that “Congress shall have the power … to promote the progress of …useful arts, by securing for limited times to …inventors the exclusive right to their …discoveries.” The U.S. Patent Office — now the U .S. Patent and Trademark Office or PTO — is one of the oldest of federal agencies, having been established in 1836 to provide an orderly and systematic examination of patent applications by professional examiners, all of whom are either engineers or scientists, and many of whom in addition have legal education and experience. The U.S. PTO is a key agency of the U.S. Department of Commerce employing more than 2500 examiners. Each of those, in turn, is assigned to examining patent applications in a very narrow area of technology. This organization permits each examiner to become an expert very quickly in his or her specific area of technology.