In Armour Packing Co. v. United States, 209 U.S. 56, 28 S.Ct. 428, 52 L.Ed. 681 (1908), the question arose as to whether a tariff could supersede a contract entered into between a railroad and a shipper (i.e., a customer). The Court found that the tariff applied, noting that the purpose of the law (i.e. the Interstate Commerce Act) 'is to require all shippers to be treated alike, and but one rate to be charged for similar carriage of freight, and that the field and published rate (be) equally known by and available to every shipper.' (209 U.S. at 80, 28 S.Ct. at 435.) In Armour, the Court emphasized the fact that the Interstate Commerce Act prescribes uniform rates for shippers and therefore cannot permit rates to be set haphazardly by contract. In Armour Packing Co. v. United States, a rate contract between a railroad and a shipper at the field rates in effect at the time the contract was made was held not to justify payment at the contract rate for shipments made after the filed rates for shipments of that character had been increased by the railroad. The very basis for that decision, however, was the requirement of the Interstate Commerce Act that rates to all shippers be uniform and comply with the single tariff filed with the Commission, there being no provision under that Act for the filing of individual contracts. In Armour Packing Company v. United States, 209 U.S. 57, 72 (1908), Mr. Justice Day, dealing with a violation of the act by carrying out a contract for a rate, after the rate had been changed by publication of a higher rate, said: "The Elkins Act proceeded upon broad lines and was evidently intended to effectuate the purpose of Congress to require that all shippers should be treated alike, and that the only rate charged to any shipper for the same service under the same conditions should be the one established, published and posted as required by law. It is not so much the particular form by which or the motive for which this purpose was accomplished, but the intention was to prohibit any and all means that might be resorted to to obtain or receive concessions and rebates from the fixed rates, duly posted and published."