Buy the hype: Director Steve McQueen's 12 Years a Slave is a powerful, stunning film—perhaps the finest ever made on the moral travesty of American slavery. It tells the true story of Solomon Northup (played by the stellar Chiwetel Ejiofor), a free man who was drugged and kidnapped in Washington, DC, in 1841 and sold into slavery. Northup, a violinist and family man based in Saratoga Springs, New York, was forced to work on Louisiana plantations for 12 years. The movie, written by John Ridley and coproduced by Brad Pitt, is based on Northup's 1853 autobiography Twelve Years a Slave.

All the film's elements—the sublime acting, the music, the unflinching depiction of slavery—conspire to create a classic in the making. As is standard with any Oscar bait that's based on an amazing-but-true story, critics and scholars are lining up to determine how well the drama stacks up to recorded history. On top of this, literary scholars have long examined and debated the "literal truth" of the film's source material. The filmmakers, fortunately, had just the right historical consultant in their corner: Henry Louis Gates Jr., the Harvard professor who edited a recent edition of Northup's memoir.

"It was refreshing how closely they followed the exact events," Gates tells Mother Jones. "But I'm not the kind of scholar who confuses a feature film with a documentary."...