In the spring of 2006, John Unsworth taught a graduate seminar on “Twentieth-Century American Bestsellers.” It led to one of history’s finest class projects–a browsable database of bestsellers, 337 in all. As with any bestseller lists, you’ll find a range of titles, everything from Thomas Wolfe to Tom Clancy, but click through and find that each entry includes an extremely detailed description of the book’s history (these were compiled by graduate students, after all); a mini-essay on its reception; images of covers, page layouts, and even some ads; and more. It is, in short, bibliophilic crack. (Thanks Craig)