There is one other restraint upon the revenue, as well as upon the commercial power, the history of which now demands our inquiries. But in order to understand it correctly, it will be necessary for the reader to recur to the position in which the revenue and commercial powers were left by the sectional compromises described in the last chapter. The struggle between the Northern and the Southern States concerning the limitations of those powers turned, as we have seen, on certain restrictions desired by the latter. They wished to have exports excepted out of the revenue power; they wished to have a vote of two thirds made necessary to the passage of any commercial regulation; and three of them wished to have the slave-trade excepted from both the revenue and the commercial powers. We have seen that the result of the sectional compromises was to leave the commercial and revenue powers unlimited, excepting by the saving in relation to the slave-trade; that they left the revenue power unlimited, excepting by the restriction concerning exports and a capitation tax; and that the commercial power was to be exercised, like other legislative powers, by a majority in Congress. General commercial and revenue powers, then, without other restrictions than these, would enable Congress to collect their revenues where they should see fit, without obliging them to adopt the old ports of entry of the States, or to consider the place where a cargo was to be unladen. They might have custom-houses in only one place in each State, or in only such States as they might choose to select, and might thus compel vessels bound from or to all the other States to clear or enter at those places. But, on the other hand, a constitutional provision which would require them to establish custom-houses at the old ports of entry of the States, without leaving them at liberty to establish other ports of entry, or to compel vessels to receive on board revenue officers before they had reached their ports of destination, would create opportunities and facilities for smuggling.