George Shiras, Jr.,
Missouri v. Illinois (180 U.S. 208…
“ While it is true that the power vested in Congress to regulate commerce among the states is a power complete in itself, acknowledging no limitations other than those prescribed in the Constitution, and that where the action of the states in the exercise of their reserved powers comes into collision with it the latter must give way, yet it is also true that quarantine laws belong to that class of state legislation which is valid until displaced by Congress, and that such legislation has been expressly recognized by the laws of the United States almost from the beginning of the government. ”
