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Continuance Spring / Summer 2003Mapping: Lewis and Clark Curriculum From An American Legacy: Lewis and Clark Expedition,
Curriculum and Resource Guide, Lewis and Clark Trail Heritage Foundation, President Thomas Jefferson was eager to know the lay of the land west of the Mississippi River, especially the major watershed of the Missouri River. The Pacific coastline of North America had been well charted by Spanish, Russian, British and American seafaring explorers and traders. In May 1792, Captain Robert Gray, an American merchant seaman, entered the mouth of the Columbia River in his ship, COLUMBIA REDIVIVA, for which the river was named. On maps in the late 1700s and early 1800s, the landscape and typography for almost two-thirds of the North American interior was blank. It was known that a continental divide existed somewhere in the west. In 1725, Daniel Coxe stated the rivers were "… separated by a ridge of hills which would prove passable by horse, foot or wagon in less than half a day." In 1772, Robert Rodgers speculated one could reach the "River Ouragan" via the headwaters of the Mississippi River and a portage of 20 miles. Thomas Jefferson proposed to the American Philosophical Society in 1793 and later in 1802-1803 a plan for the exploration of a route with a "single portage" from the Missouri River to the best water course flowing to the "Western Ocean." These were all speculations which the Lewis and Clark expedition proved untrue. In his 20 June 1803 letter of instructions to Meriwether Lewis, President Jefferson stated the need to map and document the journey of the Corps of Discovery "Beginning at the mouth of the Missouri, you will take observations of latitude & longitude, at all remarkable points on the river, & especially at the mouths of rivers, at rapids, at islands, & other places & objects distinguished by such natural marks & characters of a durable kind, as that they may with certainty be recognized hereafter. The courses of the river between these points of observation may be supplied by the compass, the log-line & by time, corrected by the observations themselves. The variations of the compass too, in different places, should be noticed. "The interesting points of the portage between the heads of the Missouri, & of the water offering the best communication with the Pacific Ocean, should also be fixed by observation, & the course of that water to the ocean, in the same manner as that of the Missouri. Your observations are to be taken with great pains & accuracy, to be entered distinctly & intelligibly for others as well as yourself, to comprehend all the elements necessary, with the aid of the usual tables, to fix the latitude and longitude of the places at which they were taken…" Lewis carried copies of the following books with him: a) to aid in scientific work: Kirwan's Elements of Mineralogy, Miller's Sexual Systems of Linneaus ( in two volumes ) and Barton's Elements of Botany; b) to aid in surveying and navigation: Nautical Almanac, Kelly's Spherics, and several ephemeris ( astronomical tables); and, c) information about the land: History of Louisiana and Vancouver's Survey of the Western Coast of North America. Equipped with the best instruments of the day, the Corps of Discovery set out to find what lay west of the Mississippi. The members of the expedition were amazed by the landscape. William Clark sketched and mapped their route. Today, nearly one hundred of Clark's field sketches of the expedition's travels and his maps make up Vol. 1 of the Moulton edition of The Journals of the Lewis and Clark Expedition. Most of the original maps are now housed in the Beinecke Collection at the Yale University library. The approximately one hundred field and compilation maps drawn by William Clark show us about the route and experiences of the Corps of Discovery. Clark was a surveyor and map maker. He used symbols to indicate topography, landmarks, direction, water conditions, Native American communities, expedition encampments and forts. Clark also added notes to his maps making them good sources of information for research projects about the Lewis and Clark expedition. Some of the mapping symbols used by Lewis and Clark are listed below. Discuss the symbols, their meanings and if they are effective in conveying good information. What other symbols might be used on the maps? Find other examples of Clark's maps in books about the Lewis and Clark expedition. Today, standardized symbols are used on maps in the United States. Discuss the features of the map such as north, measure of distance, scale, meanings of lines and symbols. Compare the maps of Lewis and Clark to the maps used today. Organize some of the following mapping activities |