Report to Congress On February 19, 1806, President Jefferson submitted to Congress a report on the finding of the Lewis & Clark expedition including "extracts of his observations, and copies of his map of the river", as well as detailed information about the many Indian tribes encountered along the way. Among the many detailed observations made by Captains Lewis & Clark and reported to Congress were; A statistical view of the Indian nations inhabitating the territory of Louisiana, and the countries adjacent to its Northern and Western Boundries, Historical Sketches of the Several Indian tribes in Louisiana, south of the Arkansas river and between the Mississippi and river Grande, A description of the Washita river, in Louisiana, and the country bourdering thereon, and Meteorological Observations.
This was the key for information provided about the Indian tribes encountered (see example of Mandan report).. The names of the Indian nations, as usually spelt and pronounced in the English language. Primitive Indian names of nations and tribes, English orthography, the syllables pronouncing the sounds by which the Indians themselves express the name of their respective nation. Nicknames, or those which have generally obtained among the Canadian traders. The language they speak; if primitive, marked with a *, otherwise, derived from , and approximating to, the. Number of villages. Number of tents, or lodges, of the roving bands. Number of warriors. The probable number of souls. The rivers on which they rove, or on which their villages are situated. The names of the nations, or companies, with whom they maintain their principal commerce or traffic. The place at which their traffic is usually carried on. The amount of merchandise necessary for their annual consumption, estimated at the St. Louis prices, in dollars. The estimated amount, in dollars, of their annual returns, at the St. Louis prices. The species of peltries, furs, and other articles, which they annually supply or furnish. The species of peltries, furs, and other articles, which the natural production of their country would enable them to furnish, provided proper encouragement was given them. The places at which it would be mutually advantageous to form the principal establishments, in order to supply the several Indian nations with merchandise. The names of the Indian nations with whom they are at war. The names of the Indian nations with whom they maintain a friendly allaince, or with whom they are united by intercourse or marriage. Miscellaneous remarks.	View portions of Lewis and Clark's report on the Mandan Indians as they appeared in the American State Papers