Hugo Black,
Hines v. Davidowitz — Opinion of the Court
“ Little aid can be derived from the vague and illusory but often repeated formula that Congress 'by occupying the field' has excluded from it all state legislation. Every Act of Congress occupies some field, but we must know the boundaries of that field before we can say that it has precluded a state from the exercise of any power reserved to it by the Constitution. To discover the boundaries we look to the federal statute itself, read in the light of its constitutional setting and its legislative history. ”
