George Matthews was struggling. An ex-Confederate medical doctor from Alabama, Matthews and his family fled the “Yankee oppression” of the Reconstruction South for the interior of São Paulo State, Brazil, hoping to grow cotton in the “pleasing” familiarity of a patriarchal, slaveholding society (156). What Matthews found was not what he expected. As cotton prices fell and he struggled to make ends meet, he was appalled to find himself the social inferior of a wealthy African-descended coffee planter, who generously offered him the opportunity to serve as his personal doctor. More distressingly, he arrived just in time to witness “a new birth of capitalism” in the state, one based not on slavery but on its abolition, which ultimately created an “agroindustrial order that no slave society had ever matched” (252, 258). The experience of Matthews, with its ironic twists of expectation and reality, is typical of Roberto Saba's fascinating American Mirror.Saba's book explores the cultural, political, and economic connections between the Western Hemisphere's largest slaveholding powers, the United States and the Empire of Brazil, during their complicated transitions from slavery to freedom. In short, Saba argues for the importance of transnational networks of American and Brazilian antislavery reformers—engineers, scientists, journalists, and entrepreneurs—to the hemispheric triumph of modern capitalism, in which the “backward and irrational” system of slavery was replaced by a system of free labor (3). As Saba makes clear, these reformers were not motivated by egalitarian concerns but by a conviction that free labor was a more efficient motor for economic development.The argument is ambitious, but Saba unfolds his case meticulously. The first three chapters are based in Brazil's imperial capital of Rio de Janeiro and chart the reception there of US diplomats, entrepreneurs, and scientists. The haughty rhetoric and filibustering ambitions of Southern statesmen did more to alienate Brazilian politicians than to unite the slaveholding powers. Northern capitalists, on the other hand, endeared themselves to Rio's elites by providing capital and expertise to build up the city's infrastructure, while abolitionist intellectuals befriended and publicly defended Brazil's emperor, convinced that his promises of gradual emancipation were sincere. The remaining three chapters turn their attention to the coffee-growing interior of São Paulo State and its dramatic transformation into an economic powerhouse. Regional elites saw free labor and mechanization as the path to prosperity and invited American capital and European landless laborers into their state, while they sent engineers, journalists, and sons of the elite to the US North, eager to witness its industrial growth firsthand.A book about the historical relationship between slavery and capitalism, American Mirror will inevitably be read in light of an already crowded field of contemporary scholarship that portrays slaveholders as “hemispheric hegemons” that were a vital part of capitalist modernization (7). But Saba's questions and concerns are provocatively different. Politically, he shows that many Brazilian elites viewed the US South not as a natural ally but as a developmental dead end, looking instead to create transnational connections with Northern capitalists, even abolitionists. And economically, he casts doubt on the entire framework of a “second slavery”—that is, that “the adoption of industrial technology and modern management techniques” could or did restore economic vitality to nineteenth-century slavery—arguing instead that these attempts were “never long-lived” and “eventually crushed by the forces they sought to control” (346). His argument gains in forcefulness as the book progresses, from its more measured presentation in the introduction to the phenomenal sixth chapter, in which the threads of his narrative come together as São Paulo State's coffee growing elite “welcomed emancipation” and ushered in a “brave new world” of industrial agriculture built on proletarianization and immiseration rather than slavery (258).The source base he uses to mount his argument is remarkable, joining private correspondence, regional political sources, and national newspapers from archives in both the United States and Brazil. And his prose is excellent throughout, with an easy-to-follow narrative that is peppered with evocative description and pithy aphorisms. Given its scope, readability, and strong presentation of a provocative position, I recommend it to anyone—nonacademics and students included—interested in the histories of slavery, capitalism, or the nineteenth-century United States and Brazil more broadly. My complaints are minor: although it suits his argument to emphasize that proslavery Brazilian planters and politicians were marginal, I found their almost total absence from the narrative to be a detriment. The reader would better understand Saba's antislavery protagonists with a clearer picture of whom they opposed. And, selfishly, I would have preferred fewer quotations from the subjects of his narrative: rather than exemplifying his points, I found they often only drew attention away from Saba's superb writing.