James Fenimore Cooper 
The Prairie 

Much was said and written, at the time, concerning the policy of adding the vast regions of Louisiana, to the already immense and but half-tenanted territories of the United States. As the warmth of controversy however subsided, and party considerations gave place to more liberal views, the wisdom of the measure began to be generally conceded. It soon became apparent to the meanest capacity, that, while nature had placed a barrier of desert to the extension of our population in the west, the measure had made us the masters of a belt of fertile country, which, in the revolutions of the day, might have become the property of a rival nation. It gave us the sole command of the great thoroughfare of the interior, and placed the countless tribes of savages, who lay along our borders, entirely within our control; it reconciled conflicting rights, and quieted national distrusts; it opened a thousand avenues to the inland trade, and to the waters of the Pacific; and, if ever time or necessity shall require a peaceful division of this vast empire, it assures us of a neighbour that will possess our language, our religion, our institutions, and it is also to be hoped, our sense of political justice.