The fur trade taught us something of our own geography upon the North
and Northwest, but it did more. It was a fur-trader who first developed
the possibilities of the Spanish Southwest for the second expansion
of our Western commerce. In 1823 General William H. Ashley, of the
American Fur Company, made an expedition up the Platte, and is credited
with first reaching from the East the South Pass of the Rockies, which
was soon to become recognized as the natural gateway of the great iron
trail across the continent. In the following year Ashley penetrated to
the Great Salt Lake, and later reached Santa Fé, situated in territory
then wholly belonging to Mexico.