The Red River Expedition (sometimes also called the Freeman-Custis Expedition) took place in the newly-acquired Louisiana Territory in the late spring and summer of 1806. Its goal, as laid out by President Thomas Jefferson, was to explore the Red River. After William Dunbar declined to lead what would have been his second expedition into the Louisiana Territory, Jefferson chose surveyor Thomas Freeman, whom he called "well qualified for the geographical part of the business."1 In total, the party consisted of Freeman, botanist Dr. Peter Custis, and thirty-five other men. Along with documenting the flora and fauna of the region, and surveying the river, they also were to meet with Indian leaders in the region, in hopes of persuading them to pledge allegiance to the United States government.2
Throughout their journey, the party was pursued by a large force of Spanish troops, estimated by Freeman to be "upwards of 1,000 in number."3 In late July, Freeman’s party was met by their pursuers, along the Red River, and a tense showdown ensued. This type of aggressive action, against supposed American territorial encroachment, was the norm during this period of tense relations; in fact a similar tactic had been attempted by the Spanish in order to halt the Lewis and Clark expedition. Luckily for all involved, the strong military tactics employed by Captain Richard Sparks, allowed the vastly outnumbered Americans to escape without incident.
Although the trip was cut short, the group was able to do some valuable work categorizing many of the local plants and animals. Perhaps most important, however, were the diplomatic talks held with the Caddo and Alabama-Coushatta tribes. These discussions laid the groundwork for increasing American control over the American Indians of the Red River region.