In United States v. Lopez, 514 U.S. 549 (1995) the United States Supreme Court considered the extent of interstate involvement an activity must have in order for it to be within the bounds of Congress's authority under the Commerce Clause of the United States Constitution. In Lopez, the Court, for the first time in 60 years, struck down an act of Congress (the Gun-Free School Zones Act) on the basis that the act exceeded Congress's Commerce Clause authority. In Lopez, Chief Justice Rehnquist broke down the previous Commerce Clause cases into three categories of things that Congress has regulated under that clause: channels of interstate commerce (by laws freeing channels of commerce from discrimination, immoral activities, etc.); instrumentalities of interstate commerce (by laws regulating safety of vehicles used in interstate commerce); and activities having a substantial relation to commerce. Lopez, 514 U.S. at 558-59. After establishing those categories, the Chief Justice acknowledged an absence of clarity in the cases dealing with the question whether, for an activity to be subject to Congressional regulation under the Commerce Clause, the activity must "affect" or must "substantially affect" interstate commerce. Id. at 559. The Court held that Congress exceeded its authority to regulate commerce in enacting the Gun-Free School Zones Act of 1990, 18 United States Code section 922, (q)(1)(A). This statute "made it a federal offense 'for any individual knowingly to possess a firearm at a place that the individual knows, or has reasonable cause to believe, is a school zone.' The Act neither regulates a commercial activity nor contains a requirement that the possession be connected in any way to interstate commerce." ( United States v. Lopez, supra, 514 U.S. at p. 551.) "Section 922(q) is a criminal statute that by its terms has nothing to do with 'commerce' or any sort of economic enterprise, however broadly one might define those terms. Section 922(q) is not an essential part of a larger regulation of economic activity, in which the regulatory scheme could be undercut unless the intrastate activity were regulated. It cannot, therefore, be sustained under our cases upholding regulations of activities that arise out of or are connected with a commercial transaction, which viewed in the aggregate, substantially affects interstate commerce." ( Id. at p. 561.)