The Free Library of Philadelphia presents this online look at one of the great nineteenth-century World's Fairs: the Centennial Exhibition of 1876, celebrating America's 100th birthday. The Website is organized into a variety of sections to help modern visitors recreate the experience of visiting the fair, but which may obscure the site's structure. The Tours section is a good starting point, featuring an interactive color panorama that's a jumping off place to major fair buildings such as the Women's Pavilion, the Horticultural Hall, or the Main Exhibition Building. Other highlights include the Centennial Schoolhouse with children's activities: a timeline, and paper model of the fair that can be printed and built. Types of historical materials presented include postcards, trade cards, wood engravings, albumen photographs, manuscripts, and children's books. In addition to the digitized historical images, the online exhibition makes heavy use of specially designed graphics, and loading these image-intensive pages may result in some long waits. For impatient types, there is a quick search box, and an advanced search for searches by subjects, captions, material types, and a link to search bibliographic records for the collection in the Free Library of Philadelphia catalog.