“ In Moore, a railroad trainman brought an action for damages based upon an alleged wrongful discharge without first exhausting administrative remedies. Federal jurisdiction was invoked on the ground of diversity; at that time an employment contract under the Railway Labor Act was thought to be governed, like ordinary contracts, by state law. The applicable law in that case-that of Mississippi-did not require exhaustion of remedies. The Court held that nothing in the Railway Labor Act required a contrary result. ”

“ In Maddox, supra, the doctrine of exhaustion of remedies was declared by this Court to be a part of this federal labor law: 'As a general rule in cases to which federal law applies, federal labor policy requires that individual employees wishing to assert contract grievances must attempt use of the contract grievance procedure agreed upon by employer and union as the mode of redress.' 379 U.S., at 652, 85 S.Ct., at 616. Strong policy arguments were adduced in Maddox to support this general rule. ”

“ Its population of some three million, if we include the families of workers, has its own customs and its own vocabulary, and lives according to rules of its own making.' Garrison, The National Railroad Adjustment Board: A unique Administrative Agency, 46 Yale L.J. 567, 568-569.' It is true of course, as the Court observes, that in the Labor Management Relations Act cases arbitration is imposed contractually while under the Railway Labor Act arbitration by the Adjustment Board is mandatory for all 'minor' contractual disputes. ”