I believe that it is no secret that I think manuscript collections are vital to genealogical research. As I was researching links for my Social History of the Day websites I came across a collection that I thought I would share.
Through the Library of Congress you can can access a digital manuscript collection about Alexander Graham Bell. This collection consists of correspondence between Bell and other family members as well as lab notes, articles, speeches and other documents. These are all available to you digitally and for free at http://memory.loc.gov/ammem/bellhtml/bellhome.html.
What a great source for those related to the Alexander Graham Bell family.