gram, the restrictions which it imposes upon the sale within the state of a commodity by its producer to a processor who contemplates doing, and in fact does work upon the commodity before packing and shipping it in interstate commerce, violate the Commerce Clause. . . .
The governments of the states are sovereign within their territory save only as they are subject to the prohibitions of the Constitution or as their action in some measure conflicts with powers delegated to the National Government, or with Congressional legislation enacted in the exercise of those powers. This Court has repeatedly held that the grant of power to Congress by the Commerce Clause did not wholly withdraw from the states the authority to regulate the commerce with respect to matters of local concern, on which Congress has not spoken. A fortiori there are many subjects and transactions of local concern not themselves interstate commerce or a part of its operations which are within the regulatory and taxing power of the states, so long as state action serves local ends and does not discriminate against the commerce, even though the exercise of those powers may materially affect it. Whether we resort to the mechanical test sometimes applied by this Court in determining when interstate commerce begins with respect to a commoddity grown or manufactured within a state and then sold and shipped out of it -- or whether we consider only the power of the state in the absence of Congressional action to regulate matters of local concern, even though the regulation affects or in some measure restricts the commerce -- we think the present regulation is within state power. . . .
In applying the mechanical test to determine when interstate commerce begins and ends . . . this Court has frequently held that for purposes of local taxation or regulation "manufacture" is not interstate commerce even though the manufacturing process is of slight extent. . . . And such regulations of manufacture have been sustained where, aimed at matters of local concern, they had the effect of preventing commerce in the regulated article. . . . A state is also free to license and tax intrastate buying where the purchaser expects in the usual course of business to resell in interstate commerce. . . . And no case has gone so far as to hold that a state could not license or otherwise regulate the sale of articles within the state because the buyer, after processing and packing them, will, in the normal course of business, sell and ship them in interstate commerce.
All of these cases proceed on the ground that the taxation or regulation involved, however drastically it may affect interstate commerce, is nevertheless not prohibited by the Commerce Clause where the regulation is imposed before any operation of interstate commerce occurs. Applying that test, the regulation here controls the disposition, including the sale and purchase, of raisins before they are processed and packed preparatory to interstate sale and shipment. The regulation is thus applied to transactions wholly intrastate before the raisins are ready for shipment in interstate commerce. . . .
This distinction between local regulation of those who are not engaged in commerce, although the commodity which they produce and sell to local buyers is ultimately destined for interstate commerce, and the regulation of those who engage in the commerce by selling the product interstate, has in general served, and serves here, as a ready means of distinguishing those