Located in a building erected in 1768 for the Philosophical Society founded in 1743 by Ben Franklin, the museum collection of approximately 3,000 artifacts and fine art objects reflects the central role of the American Philosophical Society and Philadelphia in the founding of the nation, as well as the development of science and technology from the 18th century through the early 20th century. Significant holdings include portraits of Founding Fathers; models of inventions; scientific instruments made by or relating to David Rittenhouse and other APS Members; plant specimens collected by Lewis and Clark; and several of Benjamin Franklin's personal belongings, such as a set of stencils, tall case clock, chess set, and library chair with fold-out steps.