Perhaps no American felt a yearning to tame the West more powerfully than Thomas Jefferson. Jefferson had grown up in a social circle where the men had planned an expedition to the Pacific. Since he shared his father’s avid interest in cartography, it is not surprising that he followed the reports of the explorations of the late 1700s very closely and collected many of the new publications and maps. Indeed, Thomas Jefferson himself promoted three unsuccessful attempts to find a route to the Pacific: in 1783 by George Rogers Clark (the bro ....