Red River Expedition (1806)

The Spanish officials intercepted the expedition 615 miles upriver, in what is now northeastern Texas, and turned it back before the party had achieved all of its goals.

After acquiring the lands of the Louisiana Purchase in 1803, Jefferson commissioned military groups to explore the unfamiliar territory and to collect scientific data about flora and fauna, topography, and ethnography of the many Native American peoples.

Other goals were to build trade and political relationships with the various tribes of American Indians, and to locate the Louisiana Purchase's southwestern and western borders with New Spain.

For the scientists, he chose the astronomer/surveyor Thomas Freeman, who had recently been with Andrew Ellicott on his survey of the southern boundary of the United States, and Peter Custis, who was the first academically-trained naturalist to accompany an expedition, was still a medical student in Philadelphia,[1] and served as the group's botanist and ethnographer.

[1] "Hoping to provoke an international confrontation for personal gain," U.S. General James Wilkinson of the Louisiana Territory had secretly notified Spain of the Freeman expedition (he had had separate dealings with it earlier) and sent two teams of soldiers to intercept the party.

Many in the party, led by Captain Zebulon Pike Jr., were captured in February 1807 by the Spanish after they had made mistakes in navigation and been forced to winter in New Mexico.

Spain protested officially to the U.S. about the military expedition within its territory, but as the nations were not at war, its troops escorted Pike and most of his men to the Louisiana border and released them later that year.

[6] In part because of the diplomatic furor aroused by its interception of the expedition, Spain changed its strategy and opened the Red River country to American traders.

However, Freeman's journal and Custis's pioneering natural history report gave valuable information about the American Indian peoples and the other aspects of the Red River country.