So soon, also, as this was perceived and admitted, it became a necessary consequence of the admission, that the national authority should guarantee to the people of each State the right to shape and modify their own social institutions; for without this principle laid at the foundation of the Union, there could be no peace or security for such a mixed system of government. In the second place, we have to consider the fact, that, among the political rights of the States anterior to the national Constitution, was the right to admit or to prohibit the further importation of slaves;--a traffic not then forbidden by any European nation to its Colonies, but which had been interdicted by ten of the American States. The transfer of this right to the Federal Union was a purely voluntary act; it was not strictly necessary for the purposes for which it was proposed to establish the Constitution of the United States; although there were political reasons for which a part of the States might wish to acquire control over this subject, as well as moral reasons why all the States should have desired to vest that control in the general government. Three of the States, however, as we have seen, took a different view of their interest and duty, and declined to enter the new Union unless this traffic should be excepted from the power over commerce for a period of twenty years. It is quite plain, that, if these facts had been met and dealt with in a manner different from the settlement that was actually made, one of two consequences must have ensued;--either no Constitution at all could have been adopted, or there would have been a Union of some kind, from which three at least of the States must have been excluded. If the first, by far the most probable contingency, had happened, a great feebleness and poverty of society must have continued to be the lot of all these States; there must have been perpetual collisions and rival confederacies; there certainly would have been an indefinite continuance of the slave-trade, accompanied and followed by a great external pressure upon the States which permitted it, which would have led to a war of races, or to a frightful oppression of the slaves. Most of these evils would have followed the establishment of a partial confederacy.