On March 13, 1804, Thomas Jefferson (who was President at the time) wrote to Dunbar, charging him with the task of assembling the first scientific expedition into the southern territory of the
Louisiana Purchase which was referred to as "The Great Expedition". Jefferson sanctioned four other such expeditions: the 1804
Lewis and Clark Corps of Discovery expedition to the northern territory of the Louisiana Purchase (post Dundar and Hunter), Willam Dunbar's Red River expedition of 1806, the
Red River Expedition of
Thomas Freeman and Peter Custis, and the
Pike Expedition in 1806–07. Jefferson assigned
George Hunter, a prominent Philadelphia chemist and also a Scot, to be second in command to Dunbar. The proposed southern journey was later called the
Grand Expedition. The trip was drastically altered due to friction with the Osage Indians and Spanish colonial officials, resulting in a shorter journey. On October 16, 1804, Dunbar and Hunter set off with a party of 15 on the expedition, which lasted just under three months. They explored the
Red River, Black river, and
Ouachita River. The crew brought back a wealth of scientific information, geological surveys, and records of flora and fauna. One important note from the expedition was that they recorded the first detailed chemical analysis of the
Hot Springs of Arkansas. Another expedition preliminarily named the "Great Excursion" was planned by Jefferson in order to continue the exploration of the Red River. Although Dunbar's failing health prevented him from participating in the expedition, he nevertheless was charged by Jefferson with the task of organizing it, together with Secretary of War
Henry Dearborn. Dunbar used his experience from the first Red River expedition to plan this one; among his ideas was to use a boat suited for inland river exploration in the trans-Mississippi region. This expedition was led by astronomer/surveyor Thomas Freeman and medical student Peter Custis, and it reached up the river before being halted by a Spanish military force. The Hunter-Dunbar expedition was the first American government financed expedition into the recent Louisiana Purchase. This particular expedition is somewhat overlooked because Lewis and Clark made their expansive and dramatic expeditions shortly after the Hunter-Dunbar expedition and "The Grand Expedition" was overshadowed. While Lewis and Clark's travels into then unknown territory produced some of the most expansive and well documented maps, journal writings, drawings and scientific studies, it was Hunter and Dunbar who first officially explored parts of this dangerous, unknown and mysterious territory for the American government. Originally the team was to venture only into southern regions of the Louisiana Purchase. However, their route changed several times due to trouble with the local indian tribes which eventually detoured them into southern Arkansas. "It provided Americans with the first scientific study of the varied landscapes as well as the animal and plant life of early southern Arkansas. The expedition resulted in arguably the most purely scientific collection of data among all of the Louisiana Purchase explorations". The Hunter-Dunbar expedition was extremely important to the future for the United States because the information garnered was essential to the American expansion westward. The expedition was not as long as other expeditions, but was no less relevant. The Hunter-Dunbar Expedition set many things in place for future expansion based upon their findings during their sojourn into that uncharted territory. The success of this expedition is based upon Hunter and Dunbar's extensive journal entries, their scientific observations and a few geological experiments that were conducted during the trip". Dunbar and Hunter were not the first to travel the Ouachita River or to taste the waters of the hot springs, nor were they the first to describe the region in journals or publications. They did succeed in the first scientific mapping and description of the Ouachita River valley". "As Dunbar and Hunter ascended the Red, Black and Ouachita rivers, the journals of both men became replete with descriptions of soil types, water levels, flora, fauna, and daily astronomical and thermometer readings." ==Notes==