American Heritage Magazine -- an excellent site for articles
Academy of Achievement -- Profiles, biographies and interviews with Jonas Salk (polio), Linus Pauling, James Watson (DNA), Edward Teller (atomic bomb), Chuck Yeager (breaking the sound barrier) , and others.
Inventors and Inventions-- Search for an inventor or invention alphabetically, chronologically, or by subject.
Invent Now Hall-of-Fame -- Short inventor biographies and invention impact on society
Librarians' Index to the Internet -- A collection of websites on inventors and inventions
Inventions in America -- Telephone, television, New York subway, technology timeline and forgotten inventors from PBS: American Experience: Technology
Wright Brothers' Flying Machine -- Resources that accompany the Nova TV series.
Born of Dreams -- Inspired by Freedom -- History of flight presented by the U.S. Centennial of Flight Commission
America by Air -- From the Smithsonian Museum of Air and Space
Dick Reiman's Historical Articles -- Once you've chosen an inventor/invention, look here for some extra historical tidbits, from the Institute of Electrical and Electronics Engineers.
Lemelson Center for the Study of Invention and Innovation -- From the Smithsonian Institution's National Museum of American History