Hugo Black,
Porter Company v. Central Vermont Railway…
“ The affected transportation within this country was that 'from a foreign country' over which § 1 (1) (a) specifically gives the Commission jurisdiction, and the order did nothing more than direct railroads engaged in that transportation to adjust their transportation practices 'within the United States' in such a way as to eliminate illegal discriminations. These railroads operating within the United States undoubtedly have complete power to stop these discriminations. ”
