US National Archives
Nara: Teaching With Documents: Telephone and Light Patent Drawings
A lesson plan about Alexander Graham Bell's patent for the telephone and Thomas Edison's patent for the electric lamp. Contains good background information and historically pertinent documents. It also discusses the role corporations...
PBS
Pbs: American Experience: The Telephone Goes National
This site provides information about the birth of the telephone. The site also discusses AT&T, the first long distance phone call, and the people involved.
National High Magnetic Field Laboratory
Magnet Academy: Bell Telephone 1876
Acoustics, variable resistance and allegations of foul play contribute to the exciting story of the invention of the telephone.