An unrestrained intercourse between the States themselves will advance the trade of each by an interchange of their respective productions, not only for the supply of reciprocal wants at home, but for exportation to foreign markets. The veins of commerce in every part will be replenished, and will acquire additional motion and vigor from a free circulation of the commodities of every part. Commercial enterprise will have much greater scope, from the diversity in the productions of different States. When the staple of one fails from a bad harvest or unproductive crop, it can call to its aid the staple of another. The variety, not less than the value, of products for exportation contributes to the activity of foreign commerce. It can be conducted upon much better terms with a large number of materials of a given value than with a small number of materials of the same value; arising from the competitions of trade and from the fluctuations of markets. Particular articles may be in great demand at certain periods, and unsalable at others; but if there be a variety of articles, it can scarcely happen that they should all be at one time in the latter predicament, and on this account the operations of the merchant would be less liable to any considerable obstruction or stagnation. The speculative trader will at once perceive the force of these observations, and will acknowledge that the aggregate balance of the commerce of the United States would bid fair to be much more favorable than that of the thirteen States without union or with partial unions. It may perhaps be replied to this, that whether the States are united or disunited, there would still be an intimate intercourse between them which would answer the same ends; this intercourse would be fettered, interrupted, and narrowed by a multiplicity of causes, which in the course of these papers have been amply detailed. A unity of commercial, as well as political, interests, can only result from a unity of government.