It is further contended that the authority of Congress may be exerted to control interstate commerce in the shipment of childmade goods because of the effect of the circulation of such goods in other states where the evil of this class of labor has been recognized by local legislation, and the right to thus employ child labor has been more rigorously restrained than in the state of production. In other words, that the unfair competition, thus engendered, may be controlled by closing the channels of interstate commerce to manufacturers in those states where the local laws do not meet what Congress deems to be the more just standard of other states. The grant of power of Congress over the subject of interstate commerce was to enable it to regulate such commerce, and not to give it authority to control the states in their exercise of the police power over local trade and manufacture.