Tom C. Clark,
Incres Steamship Company v. International Maritime Workers Union…
“ Therefore, in a situation where a union 'was in no way concerned with (the railroad's) labor policy,' id., at 160, 76 S.Ct. at 230, but sought to prevent motor carrier employees from delivering truck-trailers to the railroad for 'piggy-back' carriage, we held that state court jurisdiction was pre-empted by the Act. Here, of course, the IMWU's activities are directly related to Incres' employer-employee relationships, since the very purpose of those activities was the organization of alien seamen on Incres' vessels. ”
