US laws restricting business monopolies. After twenty‐five years’ agitation against monopolies, the Congress passed the Sherman Anti‐Trust Act (1890) that declared illegal ‘every contract, combination, or conspiracy in restraint of trade’. The Clayton Anti‐Trust Act (1914), amended by the Robinson–Patman Act (1936), prohibited discrimination among customers and mergers of firms that would lessen competition. After World War II there was a further growth in giant multinational corporations and the Celler–Kefauver Antimerger Act (1950) was intended to prevent oligarchic tactics, such as elimination of price competition, as being against the public interest.