The Commerce Clause (Art. I, §8, cl. 3) of the United States Constitution provides that the Congress shall have the power to regulate interstate and foreign commerce. The plain meaning of this language might indicate a limited power to regulate commercial trade between persons in one state and persons outside of that state. However, the Commerce Clause has never been construed quite so narrowly. Rather, the clause, along with the economy of the United States, has grown and become more complex. In addition, when Congress began to address national social problems, the Commerce Clause was often cited as the constitutional basis for such legislation. As a result, the Commerce Clause has become the constitutional basis for a significant portion of the laws passed by Congress over the last 50 years, and it currently represents one of the broadest bases for the exercise of congressional powers. An examination of the United States Code shows that more than 700 statutory provisions explicitly refer to either "interstate" or "foreign" commerce, covering a significant number of issues. These issues include agriculture, banking, antitrust, securities, business regulation, energy regulation, hazardous substances, consumer credit, sports regulation, the Internet, endangered species, civil rights, child support, child pornography, abortion, criminal law, controlled substances, food, firearms control, terrorism, obscenity, gambling devices, labor, industrial safety, pensions, environmental law, fish and wildlife, medical products, water pollution, atomic energy, shipping, motor vehicle safety, airplanes, and tort litigation. Since the 1990s, however, Supreme Court case law has brought the limits of the Commerce Clause into question. While these cases have resulted in the overturning of federal laws, their overall effect has so far been relatively modest in scope. A 2005 Supreme Court case, Gonzales v. Raich , seems to confirm that the effect of these previous cases will be limited. The Commerce Clause provides that "The Congress shall have Power ... To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes." The word "commerce" appears to have the same primary meaning today as it did in 1789—"an interchange of goods or commodities between different countries or between areas of the same country" or in other words "trade." However, commentators have argued that a secondary meaning of commerce which was understood at the time of the drafting of the Constitution includes all productive activity which relates to commerce, such as manufacturing and agriculture. A further question is then raised whether Congress's power to regulate commerce is significantly limited by the phrase "with foreign Nations, and among the several states, and with the Indian Tribes." For instance, the phrase "among the several States" could either be interpreted as "between people of different states" or more broadly as "between people who live in the various states." Some have argued that the broader definition, which would cover commerce between people of the same state, would render the phrase "among the several States" superfluous. This question, generally characterized as whether the power to regulate "interstate commerce" extends to "intrastate" commerce, has been mostly settled by case law, and most "intrastate" commercial transactions are vulnerable to some form of federal regulation. The integration of commercial activities in the United States was a central theme of the Constitutional Convention of 1787. It appears, however, that the parameters of the Commerce Clause were not of particular concern to the framers of the Constitution. The commentary contemporary to the Constitution on the power did not concern itself with the federalism implications of managing interstate economic transactions, but rather focused on the issue of foreign trade. The primary purpose of the clause appears to have been raising federal revenue by the nationalization of the states' power to impose import tariffs, while a secondary purpose was apparently to allow Congress to regulate and restrict foreign commerce to advance American interests. The argument has been made that while regulating free and fair trade between states was the principal motivation for adopting various other provisions of the Constitution, it may not have been a strong motivation for the drafting of the Commerce Clause. This is because state restrictions on trade between states were already prohibited under the Articles of Confederation, and the states generally complied with these restrictions. Consequently, commentary contemporary to the ratification of the Constitution indicating that the Commerce Clause was intended to limit state restrictions on interstate commerce was minimal. In Gibbons v. Ogden, the Supreme Court, in an opinion by Chief Justice Marshall, considered a challenge to a monopoly on the operation of steam-propelled vessels in New York waters. This monopoly was challenged by Gibbons, who transported passengers from New Jersey to New York under an act of Congress. The Chief Justice, in striking down the monopoly, wrote that "the power over commerce ... is vested in Congress as absolutely as it would be in a single government ..." and that "the influence which their constituents possess at elections, are ... the sole restraints" on this power. The Chief Justice went on to write that "[t]he counsel for the appellee would limit [the term commerce] to traffic, to buying and selling, or the interchange of commodities, and do not admit that it comprehends navigation. This would restrict a general term, applicable to many objects, to one of its significations. Commerce, undoubtedly, is traffic, but it is something more—it is intercourse," which the Court found easily included the issue of navigation. Marshall did qualify the word "intercourse" with the word "commercial," thus retaining the element of monetary transactions. The Court did not soon revisit this expansive view of the Commerce Clause. Instead, over the next several decades, the Court considered the boundaries of the "dormant Commerce Clause" doctrine—the implied limitation of the Commerce Clause on a state's ability to regulate commerce. This, combined with the relatively cautious exercise of the power by the early Congresses, meant that the Supreme Court did not have occasion to consider the limits of Congress's power under this doctrine for almost 60 years. When the Court again revisited Congress's power under the clause, it generally approved of statutes regulating the interstate movement of goods or persons, such as lottery tickets, adulterated food, or prostitutes. But, during the early 1900s, the Supreme Court was confronted with statutes which went beyond regulation of trade, and addressed other related economic activities. Consequently, the Court struck down a series of federal statutes which attempted to extend commerce regulation to activities such as "production," "manufacturing" or "mining." Starting in 1937, however, with the decision in NLRB v. Jones & Laughlin Steel Corporation , the Supreme Court held that Congress has the ability to protect interstate commerce from burdens and obstructions which "affect" commercial transactions. In the NLRB case, the Court upheld the National Labor Relations Act, finding that by controlling industrial labor strife, Congress was preventing burdens from being placed on interstate commerce. Thus, the Court rejected previous distinctions between the economic activities (such as manufacturing) which led up to interstate economic transactions, and the interstate transactions themselves. By allowing Congress to regulate activities which were in the "stream" of commerce, the Court also set the stage for the regulation of a variety of other activities which "affect" commerce. Subsequent Court decisions found that Congress had considerable discretion in regulating activities which "affect" interstate commerce, as long as the legislation was "reasonably" related to achieving its goals of regulating interstate commerce. Thus the Court found that in some cases, events of purely local commerce (such as local working conditions) might, because of market forces, negatively affect interstate commerce, and thus would be susceptible to regulation. The Court has also held that an activity which in itself does not affect interstate commerce could be regulated if all such activities taken together in the aggregate did affect interstate commerce. Under the reasoning of these cases, the Court has upheld many diverse laws, including laws regulating production of wheat on farms, racial discrimination by businesses, and loan-sharking. In the 1995 case of United States v. Lopez , however, the Supreme Court brought into question the extent to which Congress can rely on the Commerce Clause as a basis for federal jurisdiction. Under the Gun-Free School Zones Act of 1990, Congress 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." In Lopez , the Court held that, because the act neither regulated a commercial activity nor contained a requirement that the possession was connected to interstate commerce, the act exceeded the authority of Congress under the Commerce Clause. Although the Court did not explicitly overrule any previous rulings upholding federal statutes passed under the authority of the Commerce Clause, the decision would appear to suggest new limits to Congress's legislative authority. The Lopez case was significant in that it was the first time since 1937 that the Supreme Court struck down a federal statute purely based on a finding that Congress had exceeded it powers under the Commerce Clause. In doing so, the Court revisited its prior cases, sorted the commerce power into three categories, and asserted that Congress could not go beyond these three categories: (1) regulation of channels of commerce; (2) regulation of instrumentalities of commerce; and (3) regulation of economic activities which "affect" commerce. Within the third category of activities which "affect commerce," the Court determined that the power to regulate commerce applies to intrastate activities only when they "substantially" affect commerce. Still, the Court in Lopez spoke approvingly of earlier cases upholding laws which regulated intrastate credit transactions, restaurants utilizing interstate supplies, and hotels catering to interstate guests. The Court also recognized that while some intrastate activities may by themselves have a trivial effect on commerce, regulation of these activities may be constitutional if their regulation is an essential part of a larger economic regulatory scheme. Thus, the Court even approved what has been perceived as one of its most expansive rulings, Wickard v. Filburn , which allowed the regulation of the production of wheat for home consumption.