At that time, the entire population of the region, exclusive of the Indian tribes that roamed over its trackless spaces, was barely ninety thousand persons, of whom forty thousand were negro slaves.

The civilized inhabitants were principally French, or descendants of French, with a few Spanish, Germans, English, and Americans.
The purchase of this tremendous slice of territory could not be complete without an approval of the bargain by the United States Senate.

Great opposition to this was immediately excited by people in various parts of the Union, especially in New England, where there was a very bitter feeling against the prime mover in this business,--Thomas Jefferson, then President of the United States.

The scheme was ridiculed by persons who insisted that the region was not only wild and unexplored, but uninhabitable and worthless.

They derided "The Jefferson Purchase," as they called it, as a useless piece of extravagance and folly; and, in addition to its being a foolish bargain, it was urged that President Jefferson had no right, under the constitution of the United States, to add any territory to the area of the Republic.
Nevertheless, a majority of the people were in favor of the purchase, and the bargain was duly approved by the United States Senate; that body, July 31, 1803, just three months after the execution of the treaty of cession, formally ratified the important agreement between the two governments.