"Originality is a constitutional requirement. The source of Congress’ power to enact copyright laws is Article I, § 8, cl. 8, of the Constitution, which authorizes Congress to “secur[e] for limited Times to Authors … the exclusive Right to their respective Writings.” In two decisions from the late 19th century—The Trade-Mark Cases, 100 U.S. 82, 25 L.Ed. 550 (1879); and Burrow-Giles Lithographic Co. v. Sarony, 111 U.S. 53, 4 S.Ct. 279, 28 L.Ed. 349 (1884)—this Court defined the crucial terms “authors” and “writings.” In so doing, the Court made it unmistakably clear that these terms presuppose a degree of originality. The originality requirement articulated in The Trade-Mark Cases and Burrow-Giles remains the touchstone of copyright protection today. It is the very “premise of copyright law.”"