The National Academy of Sciences (NAS) is making 150 years of American scientific history available by publishing its entire collection of Biographical Memoirs on the Internet. Biographical Memoirs are brief biographies of deceased NAS members written by those who knew them or their work. Since 1877, NAS has published over 1,400 memoirs. Among the memoirs published online are those of famed naturalist Louis Agassiz; Thomas Edison; Alexander Graham Bell; noted anthropologist Margaret Mead; and psychologist and philosopher John Dewey. More memoirs will be published regularly until the entire collection is available online. PDF files of each memoir are available online at www.nasonline.org/memoirs.