Write a summary of the Commerce Clause and its effect on business activity, discussing the evolution of the Commerce Clause after reading excerpts from the cases: Gibbons v. Ogden, 22 U.S. 1 (1824), Wickard v. Filburn, 317 U.S. 111 (1942), Heart of Atlanta Motel Inc. v. United States, 379 U.S. 241 (1964), and United States v. Alfonso D. Lopez, Jr., 514 U.S. 549 (1995).