(standard disclaimer: these links were live in July 2012; apologies in advance if they're no longer active)

General Resources for the year 1900

American Experience/ PBS: 1900 website
Brief overview of the year 1900, Library of Congress American Memory
Digital History (online textbook) - The United States in 1900
Short list of facts from American Digest - America in 1900
US Census Bureau "Fast Facts" about 1900-1909

1900 Paris Exposition

National Gallery of Art - stereographs of the Exposition
Brooklyn Museum - Exposition photographs (some colorized), see also their Flickr set

Lumiere footage from the Exposition (although set to non-period music)

Exhibit of American Negroes at the Paris Exposition

Henry Louis Gates, Jr. "The Talented Tenth in Pictures" (The Root, 2010)
David J. Cope, Lesson Plan "W.E.B. DuBois and the 1900 Paris Exposition" (source: The History of Jim Crow)
Links, resources and photographs, from WEBDuBois.org
Historical/archival digital reconstruction of the Paris Exposition, including "The Exhibit of American Negroes"
The Negro Exhibit on "Edwardian Promenade"
Library of Congress collection of 200+ photographs assembled for the exposition
"About DuBois and the Paris Exhibition" - graduate student project website that contains an image of what the installation looked like