The exercise of the treaty making power, the power of dealing with foreign nations, presents a subject of peculiar difficulty to a federal state such as ours in which the component states exercise sovereign power in local matters, for treaty making does not relate, as some persons seem to think, only to matters lying beyond the boundaries of the country. Treaties regulate our relationships with foreign nations and peoples; and these relationships concern matters which are subject to regulation at our end of the relationship by the several states of our union. Treaties of friendship, commerce and navigation relate to the rights of our citizens to trade, travel and carry on business in foreign countries and of the citizens of such countries t...