Interesting comparison: Princeton English professor William Gleason compares the [Potter] series' impact to the frenzy that surrounded Uncle Tom's Cabin before the Civil War. "That book penetrated all levels of society," he says. "It's remarkable how similar the two moments are." Full article here.
Rising abolition sentiment in New England and the controversial Fugitive Slave Act of 1850 helped propel Uncle Tom's Cabin to huge best seller status when published in 1852.
Pictured is the 2-volume first edition currently offered at $15,000 by Between the Covers booksellers. They describe Harriet Beecher Stowe's novel as "the best-selling novel of the 19th Century, it spawned numerous offshoots and dramatic adaptations, and so polarized the nation over the issue of slavery that, according to legend, upon meeting Stowe, Abraham Lincoln jokingly cited it as the cause of the Civil War. Perhaps not the most famous novel ever written, and certainly not the best, but probably the single novel to exert the greatest direct influence on the course of American and world history."