States. And as in Canada one man, Mackenzie, had been the pivot about which far west explorations turned, so in this country the central influence moulding policies and determining results was likewise a unique individual, Thomas Jefferson.
Sources of Jefferson's interest in the west. Jefferson's interest in the west had two sources, environment and philosophy. We know that his Piedmont home was practically at the frontier of Virginia where his father, Peter Jefferson, established himself as a pioneer about the year 1737. Probably this fact helps to explain the heartiness of Jefferson's sympathy with all things western. But, on the other hand, Jefferson was perhaps the most perfect American representative of the type of eighteenth century philosopher. He was passionately fond of knowledge and he had a strong bent for investigation. This caused him to look into questions of every sort, and problems in geography or in natural history appealed to him powerfully. The fact that a great portion of the American continent was as yet unexplored insured Jefferson's special interest in that region. He was restlessly anxious to learn all those facts about it that were still unknown. But as he saw "the works of nature in the large," to use his own phrase, the great features of its geography, like its mountains and water courses, were to him of paramount interest.
The Missouri and its connections as Jefferson saw them in 1781–2. In the years 1781 and 1782 Jefferson wrote a greographical and political work entitled