“ Based on this fundamental law, the authority of Congress extends to a larger proportion of private business than had probably ever been foreseen by the fathers of the country. For not only may it regulate inter-state transportation and passenger service on railroads, but it may also impose conditions on how business may be done between firms in one State and its patrons, or other firms, in other parts of the country. ”

“ Congress has jurisdiction over harbors, even though they may be inclosed entirely by the territory of one state, and has the authority to grant concessions for harbor works. It may authorize and compel the removal of rocks or the dredging of rivers, to facilitate transportation and passenger traffic. It is within the jurisdiction of Congress to guard against dangers to the lives of travelers, to the extent that it can compel steamship or railroad companies to adopt safety appliances, should it deem such devices effective. ”

“ A great deal of Federal legislation has been passed, based on this Constitutional clause, the most important of which is the Sherman Anti-Trust Law, passed in 1890, which forbids combinations of manufacturers or traders tending toward monopoly, and so “restraining” the natural laws of supply and demand. ”