Justice Jackson delivered the opinion of the Court.

…[Roscoe C. Filburn] for many years past has owned and operated a small farm in Montgomery County Ohio, maintaining a herd of dairy cattle, selling milk, raising poultry, and selling poultry and eggs. It has been his practice to raise a small acreage of winter wheat, sown in the Fall and harvested in the following July; to sell a portion of the crop; to feed part to poultry and livestock on the farm, some of which is sold; to use some in making flour for home consumption; and to keep the rest for the following seeding. The intended disposition of the crop here involved has not been expressly stated.

In July of 1940, pursuant to the Agricultural Adjustment Act of 1938, as then amended, there were established for [Filburn's] 1941 crop a wheat acreage allotment of 11.1 acres and a normal yield of 20.1 bushels of wheat an acre. He was given notice of Such allotment in July of 1940 before the Fall planting of his 1941 crop of wheat, and again in July of 1941, before it was harvested. He sowed, however, 23 acres, and harvested from his 11.9 acres of excess acreage 239 bushels, which under the terms of the Act ... constituted farm marketing excess, subject to a penalty of 49 cents a bushel, or $117.11 in all. [Filburn] has not paid the penalty and he has not postponed or avoided it by storing the excess under regulations of the Secretary of Agriculture....

The general scheme of the Agricultural Adjustment Act of 1938 as related to wheat is to control the volume moving in interstate and foreign commerce in order to avoid surpluses and shortages and the consequent abnormally low or high wheat prices and obstructions to commerce. Within prescribed limits and by prescribed standards the Secretary of Agriculture is directed to ascertain and proclaim each year a national acreage allotment for the next crop of wheat, which is then apportioned to the states and their counties, and is eventually broken up into allotments for individual farms. Loans and payments to wheat farmers are authorized in stated circumstances.

The Act provides further that whenever it appears that the total supply of wheat as of the beginning of any marketing year ... will exceed a normal year's domestic consumption and export ... a compulsory national marketing quota shall be in effect with respect to the marketing of wheat.... [T]he Secretary must ... conduct a referendum of farmers who will be subject to the quota to determine whether they favor or oppose it; and if more than one third of the farmers voting in the referendum do oppose, the Secretary must prior to the effective date of the quota by proclamation suspend its operation....

Pursuant to the Act, the referendum of wheat growers was held on May 31, 1941. According to the required published statement of the Secretary of Agriculture, 81 per cent of those voting favored the marketing quota, with 19 per cent opposed….

It is urged that under the Commerce Clause of the Constitution, Article I, Sec. 8, clause 3, Congress does not possess the power it has in this instance to exercise. The question would merit little consideration since our decision in United States v Darby *** sustaining the federal power to regulate production of goods for commerce except for the this Act extends federal regulation to production not intended in any part for commerce but wholly for consumption on the farm. The Act includes definition of "market" and its derivatives so that as related to wheat in addition to its conventional meaning also means to dispose of "by feeding (in any form) to poultry or livestock which are sold, or the products are sold, bartered, or exchanged, or to be so disposed of." Hence, marketing quotas not only embrace all that may be sold without penalty but also what may be consumed on the premises. Wheat produced on excess acreage is designated as "for marketing" as so defined and the penalty posed thereon. Penalties do not depend upon whether any part of the wheat either within or without the quota is sold or intended to be sold. The sum of this is that the Federal Government fixes a quota including all that the farmer may harvest for his own farm needs, and declares that wheat produced on excess acreage may neither be disposed of nor used except upon payment of the penalty or except it is stored as required by the Act or to the Secretary of Agriculture.

[Filburn] says that this is a regulation of production and consumption of wheat. Such activities he urges are, beyond the reach of congressional power under the Commerce Clause, since they are local in character, and their effects upon interstate commerce are at most "indirect." In answer the government argues that the statute regulates neither production nor consumption, but only marketing; and, in the alternative, that if the Act does go beyond regulation of marketing it is sustainable as "necessary and proper" implementation of the power of Congress over interstate commerce.

The Government's concern lest the Act to be held to a regulation of production or consumption rather than of marketing is attributable to a few dicta and decisions which might be understood to lay it down that activities such as "production," "manufacturing" and "mining" are strictly "local" and, except in special circumstances which are not present here, cannot be regulated under the commerce power because their effects upon interstate commerce are, as a matter of law, only "indirect." Even today when this power has been held to have great latitude there is no decision of this Court that such activities may be regulated where no part of the product is intended for interstate commerce or intermingled with subjects thereof. We believe that a review of the course decision under the Commerce Clause will make plain, however, that questions of the power of Congress are not to be decided by reference ;or any formula which would give controlling force to nomenclature such as "production" and "indirect" and foreclose consideration of the actual effects of the activity in question upon interstate commerce.

,At the beginning Chief Justice Marshall described  the federal commerce power with a breadth never yet exceeded. *** He made emphatic the embracing and penetrating nature of this power by warning that effective restraints on its exercise must proceed from political rather than from judicial processes. ***

For nearly a century, however, decisions of this Court under the Commerce Clause dealt rarely with questions of what Congress might do in the exercise of its granted power under the Clause and almost entirely with the permissibility of state activity which it was claimed discriminated against or burdened interstate commerce. During this period there was perhaps little occasion for the affirmative exercise of the commerce power, and the influence of the Clause on American life and law was a negative one, resulting almost wholly from its operation as a restraint upon the powers of the states. In discussion and decision the point of reference, instead of being what was "necessary and proper" to the exercise by Congress of its granted power, was often some concept of sovereignty thought to be implicit in the status of statehood. Certain activities such as "production;' "manufacturing," and "mining" were occasionally to be within the province of state governments and beyond the power of Congress under Commerce Clause.

It was not until 1887 with the enactment of Interstate Commerce Act that the interstate commerce power began to exert positive influence in American law and life. This first important federal resort to the commerce power was followed in 1890 by the Sherman Anti-Trust Act and, thereafter, mainly after 1903, by many others. These statutes ushered in new phases of adjudication, which required the Court to approach the interpretation of the Commerce Clause in the light of an actual exercise by Congress of its power thereunder.

When it first dealt with this new legislation, the Court adhered to its earlier pronouncements, and all but little scope to the power of Congress. *** ...

Even while important opinions in this line of restrictive authority were being written, how other cases called forth broader interpretation of the Commerce Clause destined to supersede the earlier ones,-and to bring about a return to the principles first enunciated by Chief Justice Marsh Gibbons v. Ogden. *** ...

The Court's recognition of the relevance of economic effects in the application of the Commerce Clause ... has made the mechanical application of legal formulas no longer feasible. Once an economic measure of the reach of the power granted to Congress in the Commerce Clause is accepted, questions of federal power cannot be decided simply by finding the activity in question to be "production" nor can consideration of its economic effects be closed by calling them "indirect."...

Whether the subject of the regulation in question was "production," "consumption;' or "marketing" is therefore, not material for purposes of deciding the question of federal power before us. That an activity is of local character may help in a doubtful case to determine whether Congress intended to reach it. The same consideration might help in determining whether in the absence of congressional action it would be permissible for the state to exert its power on the subject matter, even though in so doing to some degree affected interstate commerce. But if [Filburn's] activity be local and though it may not be regarded as commerce, it may still, whatever its nature, be reached by Congress if it exerts a substantial economic effect on interstate commerce, an irrespective of whether such effect is what at some earlier time have been defined as "direct" or indirect."

The wheat industry has been a problem industry for some years.... The decline in the export trade has left a large surplus in production which in connection with an abnormally large supply of wheat and other grains in recent years caused congestion in a number of markets; tied up railroad cars; and caused elevators in some instances to turn away grains, and railroads to institute embargoes to prevent further congestion....

In the absence of regulation the price of wheat in the United States would be much affected by world conditions....

The effect of consumption of home-grown wheat on interstate commerce is due to the fact that it constitutes the most variable factor in the disappearance of the wheat crop. Consumption on the farm where grown appears to vary in an amount greater than 20 per cent of average production. The total amount of wheat consumed as food varies but relatively little, and use as seed is relatively constant.

The maintenance by government regulation of a price for wheat undoubtedly can be accomplished as effectively by sustaining or increasing the demand as by limiting the supply. The effect of the statute before us is to restrict the amount which may be produced for market and the extent as well to which one may forestall resort to the market by producing to meet his own needs. That [Filburn's] own contribution to the demand for wheat may be trivial by itself is not enough to remove him from the scope of federal regulation where, as here, his contribution, taken together with that of many others similarly situated, is far from trivial, ***

It is well established by decisions of this Court that the power to regulate commerce includes the power to regulate the prices at which commodities in that commerce are dealt in and practices affecting such prices. One of the primary purposes of the Act in question was to increase the market price of wheat and to that end to limit the volume thereof that affect the market. It can hardly be denied that a factor of such volume and variability as home-consumed wheat would have a substantial influence on and market conditions. This may arise because being in marketable condition such wheat overhangs the market and if induced by rising prices tends to flow into the market and check price increases. But if we assume that it is never marketed, it supplies a need of the man who grew it which would otherwise be reflected by purchases in the open market. Homegrown wheat in this sense competes with wheat in commerce. The stimulation of commerce is a use of the regulatory function quite as definitely as prohibitions or restrictions thereon. This record leaves us in no doubt that Congress may properly have considered that wheat consumed on the farm grown if wholly outside the scheme of regulation would have a substantial effect in defeating and obstructing its purpose to stimulate trade therein at increased prices.

It is said, however, that this Act, forcing farmers into the market to buy what they could provide for themselves, is an unfair promotion of the markets and prices of specializing wheat growers. It is of the essence of regulation that it lays a restraining hand on the self-interest of the regulated and that advantages from the regulation commonly fall to others. The conflicts of economic interest between the regulated and those who advantage by it are wisely left under our system to resolution by the Congress under its more flexible and responsible legislative process. Such conflicts rarely lend themselves to judicial determination. And with the wisdom, workability, or fairness, of the plan of regulation we have nothing to do....