Today the Library of Congress debuts an exhibition celebrating the early exploration of North America, with a focus on the work of Meriwether Lewis and William Clark. The exhibit, on display until Nov. 29, details the expansive timeline of geographical discovery in the United States and its position relative to the world.

‘Rivers, Edens, Empires: Lewis & Clark and the Revealing of America” includes the only known remaining 1507 world map produced by cartographer Martin Waldseem ller. The cornerstone of the exhibit, the map is in 12 sections totaling 36 square feet of remarkably accurate longitudinal detail. Although the map appears distorted, John Hebert, chief of the Library’s geography and map division, commented, ‘Distortion is not from the map, but how the map is projected, with the land compressed on the edges. If you pull it and adjust it, it’s amazing how accurate it is.”

The map is in mint condition, thanks to its forgotten status during much of the tumultuous 350 years it spent in a castle in southern Germany. Rediscovered in 1901 and preserved in a portfolio case until now, the map was recently purchased by the Library for $10 million from Prince Johannes Waldburg-Wolfegg.

‘It was found in south Germany, but had endured war among other things because it was protected in a portfolio,” Hebert said. ‘It was not on a wall where wind or rain could destroy it.”

The Library of Congress plans to keep the original in place for much of the exhibition but will have to alternate it with a full-size facsimile toward the end and later, as it hangs in its permanent display. LOC Interpretive Programs Officer Irene Chambers said the substitution is necessary because of the negative effects of light exposure on ancient documents and the desire to preserve the item for future museum-goers.

The Waldseem ller map is merely the beginning of the exhibition. Designed in three sections, the artifacts are organized to detail discovery. Chambers says the exhibit can be deceptive in its scope. ‘It contains a prologue, before Lewis and Clark, a Lewis and Clark section, and then documents from after Lewis and Clark. It seems simple. It gets very complicated as you realize how much it took to get there.”

The exhibit, made up of items from the LOC and materials on loan from several museums, contains more than 200 items spanning the three sections, including maps, diaries, prints, artifacts, letters from President Thomas Jefferson, detailed instructions, medical tools, and plant and animal specimens. Highlights include three digital displays that allow museum visitors to trace the path of Lewis and Clark, state by state, as well as an interactive map originally produced by Nicholas King. The display illuminates how King combined the works of cartographers — including Captain George Vancouver, Aaron Arrowsmith and Alexander Mackenzie — to produce the map Lewis carried with him and annotated as he proceeded westward.

Details and images from the collection can be found at www.loc.gov/exhibits/lewisand clark/preview.html.