The Impending Crisis of the South: How to Meet It is an 1857 book by Hinton Rowan Helper, who declares himself a proud Southerner.^: vi It was written mostly in Baltimore, but it would have been illegal to publish it there, as he pointed out.^: 360 It was a strong attack on slavery as inefficient and a barrier to the economic advancement of whites. The book was widely distributed by Horace Greeley and other antislavery leaders, and infuriated Southerners. According to historian George M. Fredrickson, "it would not be difficult to make a case for The Impending Crisis as the most important single book, in terms of its political impact, that has ever been published in the United States."^: 542 In the North it became "THE book against slavery."^: 75 A book reviewer wrote, "Next to Uncle Tom's Cabin (1852), Hinton Helper's critique of slavery and the Southern class system, The Impending Crisis of the South (1857), was arguably the most important antislavery book of the 1850s."