vast stretches of forest for hunting grounds, and would be glad to sell these to the government for money or needed supplies. That is why Jefferson dwells at such length upon the importance of maintaining government trading houses, where they already existed among Indian tribes, and urges Congress to consider carefully the question of establishing others. The Mississippi River, and the question of how to defend it, lie back of this entire discussion.
When we come to the second part of the message other questions appear, but the argument for the protection of the Mississippi still applies if instead of a French danger we will substitute a British danger as the inciting cause.
Fear of British designs on Upper Mississippi. We have seen how Mackenzie believed that the boundary between the United States and Great Britain in the Northwest would be completed by drawing a line to a navigable point on the Mississippi, say just below St. Anthony's Falls in latitude forty-five degrees, and that he insisted also on drawing a line from that point west "until it terminates in the Pacific Ocean to the south of the Columbia."
Since the northern boundary of Louisiana, which was then still a Spanish territory, had never been definitely ascertained, it might not have proved difficult for Great Britain to push her boundary south to the fortyfifth parallel, or even lower. But it was clearly against the interest of the United States that she would do so, because it would endanger the upper Mississippi even
