The Digital Dance Archives is the result of an AHRC-funded research project carried out by academics and archive staff at the University of Surrey (DFT and CVSSP), National Resource Centre for Dance (NRCD) and Coventry University. The Archive represents over 100 years of British dance. There are photographs, artworks and videos. It is an important resource for dance research.
The Performing Arts Encyclopedia is a Library of Congress resource in which you can explore music theatre and dance. Library of Congress has extensive archives for research into dancers such as Cole, Hawkins, Nuryev, and St. Denis and many more, though unfortunately these resources are not online. The encyclopedia has, however, an excellent online resource for the modern dance exponents Martha Graham, and Katherine Dunham. The Martha Graham Collection gives photographs and information on all of her 166 ballets, with press cuttings of reviews. The Dunham Collection includes videos demonstrating Dunham techniques. There is also an online Aaron Copeland Collection which can be browsed by title, composition, and correspondence.