Old Patent Office Building (now Smithsonian American Art Museum and National Portrait Gallery)

The Old Patent Office Building, designed by Robert Mills and completed in the mid-19th century, housed the U.S. Patent Office and its large collection of patent models and related records during the 19th century. The building served as a central federal repository for patent-related materials and documentation that historians use to study the development and diffusion of 19th-century American technologies. Its surviving structure and archival associations make it a documented physical site of early U.S. technological administration and invention.