Some Online Resources for Mark Twain

MT IN HIS TIMES ICON
Mark Twain In His Times: An Electronic Archive
This is the site I've been building since 1996, with resources from the Barrett Collection, UVA Special Collections.
MT PROJECT ICON
Mark Twain Project Online
This site is being built by the Mark Twain Project at the University of California, Berkeley. It has a lot of material about Huck Finn, but is especially valuable for its searchable collection of over two thousand Sam Clemens|Mark Twain letters, written through 1880.
MT QUOTATIONS ICON
Mark Twain Quotations, Newspaper Collections, & Related Resources
This rich site is the work of Barbara Schmidt, featuring a quotation from MT for every occasion, scores of contemporary newspaper articles by and (mainly) about MT, and many great graphics from the collection of Dave Thompson.