William Henry Ashley was born a poor man in Powhatan County,Virginia in 1778. He later moved to St. Genevieve, Mo. (then Upper Louisiana), in 1803. This area had been controlled by the Spanish until late 1800 when it was ceded by Spain to France. On Easter, 1803, Napoleon announced his decision to sell the Louisiana Territory to the United States. Ashley was in this new territorty the year that it became part of the U.S. He arrived in this new territory with "a knowledge of surveying and a slight familiarity with geology".
Lewis & Clark began their historic expedition from near St. Louis May 21, 1804 and returned to St. Loius on Sept. 23, 1806. They used the Missouri and Yellowstone Rivers much the same way that Ashley and his men would in later years.
Ashley moved to St. Louis around 1808 and became a Brigadier General in the Missouri Militia during the War of 1812. Before the war, he operated a gunpowder factory after discovering a cave in Texas County, Missouri that was a source of saltpeter, a vital ingredient of gunpowder. His future partner, Andrew Henry owned a factory that produced bullets. This is how the two earned their first fortunes.