Since 1789, this two-story, late Georgian brick building has been the home of one of America's oldest and most honorable learned and scientific societies. The American Philosophical Society traces its origins back to 1743, when Benjamin Franklin publicly urged the creation of a society to stimulate interest in learning. In addition to providing a central meeting place for its members, the American Philosophical Society Hall served many purposes in its early years. Portions of it were leased to the University of Pennsylvania and to artist Thomas Sully for his portrait studio, and the basement was used as a wine cellar for an import business. Most notably, the Hall became the first home of Charles Willson Peale's famous natural history museum (before it was moved to Independece Hall) which included specimens of all kinds of plants and animals, including the giant bones of an extinct mastodon. The Society's journal, Transactions, continues as the country's oldest scholarly periodical. Over the years the Society has counted America's intellectual elite among its members. President Thomas Jefferson was one, and 10 years before the Corps of Discovery, Jefferson proposed that the American Philosophical Society outfit an adventurer to explore the American continent. A teenage Meriweather Lewis volunteered to lead this expedition but was deterred by Jefferson. Jefferson ultimately chose André Michaux, a French botanist, to lead this exploration. Although the Michaux expedition was called off, the Society became entertwined with the exploration of the American west. During Lewis's stay in Philadelphia during the Spring of 1803, he took crash courses in a variety of disciplines that he and Jefferson thought would be necessary as leader of the expedition. Among those he consulted were physician Dr. Benjamin Rush and anatomist Dr. Caspar Wistar, both members of the Society.

A selection of the journals of Lewis and Clark Courtesy of the American Philosophical Society

After the Corps of Discovery disbanded in 1806, many of Lewis and Clark's journals were deposited in the collections of the American Philosophical Society at Jefferson's urging. Some editors of the journals argued that the excellent condition of these journals indicates that they were fair copies made after the end of the expedition in September of 1806, and prior to Jefferson's receiving them at the end of the year. Others, however, suggest that the story is more complex. The American Philosophical Society collection consists of 18 small notebooks, approximately 4 by 6 inches, of the type commonly used by surveyors in field work. Thirteen of these are bound in red morocco leather, four in boards covered in marbled-paper, and one in plain brown leather, and there are a number of loose pages and rough notes as well. The available evidence suggests that Lewis and Clark carried their notebooks sealed in tin boxes that were intended to protect the relatively fragile journals from the elements. If nothing else, with Jefferson's advising, the journals were considered invaluable as the only reliable record of data gathered on the expedition. It seems likely, therefore, that great care would be taken in their preservation. From a close examination of the journals and sets of loose notes, noted Lewis and Clark historian Gary Moulton, among others, has concluded that Lewis and Clark often worked from rough notes compiled daily, then periodically transcribed these into more polished form in the bound volumes, however in most cases, the time between taking the notes and transcribing them must have been very brief. On many occasions, the explorers clearly wrote directly into the bound volumes. The journals contain huge volumes of data, going beyond geographical notes and records of temperature and weather. Both men made meticulous observations on the geology and biology of the region and enlivened their journals with images of animals and plants, American Indian artifacts, canoes and clothing. Today, the journals remain an invaluable record of the journey. The Hall recently opened its doors to the public for the first time since the early 19th century. On view are exhibitions that explore the intersections of history, art and science, with a focus on the early days of Philadelphia and the nation.

The American Philosophical Society Hall, a National Historic Landmark, is located at 104 South Fifth St., in Philadelphia, Pennsylvania. It is part of Independence National Historical Park, administered by the National Park Service. The Hall is open year round from 12:00pm to 5:00pm; from April-September it is open Wednessday-Sunday; October-March is is open Thursday-Sunday. The Library, located across Fifth St., is open to researchers 9:00am to 4:45pm, Monday-Friday, except holidays. Please notify the Library at least 24 hours in advance of any visit by calling 215-440-3400. Visit the American Philosophical Society online at www.amphilsoc.org.