Constitution did not empower Congress to regulate purely private agreements but instead authorized Congress only to remove barriers to interstate commerce erected by individual states. They argued that even if Congress possessed the authority to regulate purely private agreements, banning defendants' cartel would infringe liberty of contract because the defendants' cartel purportedly set reasonable prices. The defendants' last argument was that their cartel did not directly restrain trade but was simply a partial restraint, which ensured the defendants merely a reasonable rate of return and thus would have been enforceable at common law. The Court, in an opinion by Justice Peckham, rejected all three arguments and affirmed the decision of the Court of Appeals. Peckham conceded that the framers and ratifiers of the Constitution likely anticipated that the Commerce Clause would authorize mainly Congressional interdiction of state-created barriers to interstate commerce. At the same time, Peckham observed that in some cases, purely private agreements can have the same economic impact and directly restrain commerce among the several states. Moreover, Peckham also held that contracts that directly restrain trade are not the sort of ordinary contracts and combinations that find shelter in liberty of contract. Finally, Peckham held that the defendants' cartel directly restrained trade. Peckham quoted extensively from Judge Taft's opinion below, which found, as a matter of fact, that the defendant's cartel set unreasonable prices. See 85 F. 291-93. In particular, Peckham quoted Taft's finding that pipe produced by the cartel could have been produced and delivered to Atlanta for a cost, including a reasonable profit and the cost of transportation, or $17 or $18 per ton, but the cartel charged instead $24.25 per ton. See also US antitrust law List of United States Supreme Court cases, volume 175 Notes Further reading Fiss, Owen M. Troubled beginnings of the modern state, 1888-1910 (1993) pp 125-59. Online External links United States Supreme Court cases United States Supreme Court cases of the Fuller Court United States Court of Appeals for the Sixth Circuit cases United States antitrust case law 1898 in United States case law William Howard Taft United States contract case law Piping