On their way west, Lewis and Clark carried a copy of A map exhibiting all the new discoveries in the interior parts of North America ... . When Jefferson met with French ambassador Louis Andre Pichon in 1803, he traced what became the Lewis and Clark trail on this map.

Perhaps the most important document for exploration of the West was Jefferson's Instructions for Meriwether Lewis. In this letter, the third president drafted a plan for western exploration "for the purposes of commerce." The letter became the charter for federal exploration for the remainder if the 19th century.

In addition to maps and manuscripts, the exhibition will display objects such as William Clark's compass and case, an Indian peace pipe, or calumet, and a blunderbuss, or gun like one that would have accompanied the explorers.

The Geography and Map Division of the Library has the world's largest collection of cartographic materials - more than 4.5 million items. Many of its maps are online in Map Collections: 1500-2003. One advantage of viewing these maps online is that you can zoom in and see them with greater clarity than with the naked eye. A technology called MrSID makes it possible. A recent and very noteworthy acquisition by this division is the map by Martin Waldseemuller of North America. The map is the opening display in this new exhibition. (See the "Map" story in this issue for further details on why this map is so important to the history of America.)

Other presentations on this Web site that relate to Western exploration include "History of the American West 1860-1920," "The First American West: The Ohio River Valley, 1750-1820," "Trails to Utah and the Pacific: Diaries and Letters, 1846-1869," "American Indians of the Pacific Northwest" and Reclaiming the Everglades: South Florida's Natural History, 1884-1934." These are all from the American Memory collections of 8 million items from the Library and other repositories. If you type in "exploration" in the American Memory Collection Finder Search Page, you will gain access to thousands of images, maps, manuscripts and other materials relating to this fascinating topic.

If you are in Washington between now and Nov. 29, don't miss the opportunity to see "Rivers, Edens, Empires." It is on view in the Thomas Jefferson Building, at the corner of First Street and Independence Ave. S.E. (across First Street from the U.S. Capitol), Monday through Saturday, 10 a.m. - 5 p.m. If not, then enjoy the virtual exhibition at the Exhibitions home page, where more than 40 other exhibitions await your exploration.