In 1924, American reformers seeking an end to the labor of children believed they were on the verge of a historic victory. For two decades, the National Child Labor Committee had pushed for federal regulation. Their successes—the 1916 Keating-Owen Act and the 1919 Child Labor Tax—had been encouraging but fleeting, as the US Supreme Court had ruled both unconstitutional. Now they sought a constitutional amendment to give the federal government the power to do what the court said it could not. Congress passed the amendment, which went to the states with broad, influential support. All three major presidential candidates endorsed it. Progressives pitied their opponents, a motley assortment of traditionalists. Some dismissed them as pawns of greedy manufacturers who had long fought to keep children at work. But these over-confident champions of reform would not get to celebrate. Their opponents racked up win after win against the amendment, from states in the predictably anti-reform South to Massachusetts. By 1925, the child labor amendment was considered lost.Betsy Wood culminates her smart, tightly argued history of the political struggle to end child labor with the story of this last gasp of Progressive Era reform. The amendment's failure, she contends, not only marked the “emergence of a collective resistance to the modern bureaucratic state” but also revealed how American thinking about child labor reflected broader understandings of the moral and social consequences of capitalism (146). As Wood makes clear, the child labor question had long been a flashpoint in American debates about the nation's political traditions, racial regimes, and gender roles. With a primary focus on campaigns to curtail child labor, Wood traces this “ideological and political struggle” back to the 1850s, when northern reformers began to differentiate good child labor from bad, a process that drew on free labor ideas and gained urgency amid the sectional crisis over slavery (1). Debates over child labor became a primary means by which the fight between regimes of free and unfree labor continued to shape the way northerners and southerners adapted to industrial capitalism after emancipation.Wood locates the origins of child labor reform in antebellum free labor ideology that valorized manly independence through “good” work. Increasingly anxious about industrial capitalist labor demands in cities, the Children's Aid Society sought to rescue poor white boys from dependence by sending them west to work on farms. There they believed that boys would earn their independence to become free republican citizens and good white men. Northern reformers in the 1870s and 1880s included immigrant and Black children among those in need of advocacy, but in so doing they reinforced a sectional and inherently racialized framework for understanding bad child labor. Once these reformers fashioned concepts of good child labor that relied on comparisons to slavery, they entrenched a conceptual relationship that would shape and limit the rhetoric and politics of reform for decades.It was southern reformers who revitalized the movement against child labor after 1901, when Edgar Gardner Murphy founded the Alabama Child Labor Committee to bar children from textile mills. Wood explains how the rapid growth of industrial capitalism exacerbated fears that white children who worked in factories would be made permanently dependent, creating the basis for intersectional consensus among white Progressives in an age of Jim Crow and imperial expansion. Murphy gave old free labor arguments against child factory labor new salience by claiming that mill work now threatened white racial degeneracy and the downfall of American civilization. Northerners rallied to fight “white child slavery” (52). With the creation of the national committee in 1904, the cause seemed to overcome sectional animosities; it included such unlikely allies as Ben Tillman and Jane Addams. Twelve states passed new regulations. Once awakened, however, northern Progressives went full abolitionist, with calls for federal action. “Likening the abolition of child labor to slave emancipation,” Wood argues, “the movement embarked on a religious crusade to shame capitalists and achieve federal intervention” (85).Righteous fury helped northern reformers achieve federal legislation with Keating-Owen, but antagonized sectional politics—southern politicians and mill owners dug in to resist reform. When the Supreme Court ruled in favor of southern complainants in 1918, northern reformers found themselves caught between old arguments and new realities born of the Great War's mobilization of capitalism. Rather than press appeals to the moral virtues of free labor, they now embraced secular arguments about the developmental value of childhood, especially the importance of play. They argued that no children should work, in factories or on farms. Wood deploys a brilliant analysis of the cultural power of the toy industry—soldiers and building kits for boys, dolls for girls—to demonstrate how northern reformers recast children as important national resources as future citizens and consumers while deflecting attention from the capitalists who continued to employ them as workers.In the constitutional fight that followed, Wood shows, northern reformers ceded older moralistic arguments rooted in free labor ideology in favor of “a new market orientation toward consumerist values of personal growth and fulfillment guaranteed by a modern progressive state” (5). Southern opponents, directed by organized capital, turned the old free labor arguments against reform. With an expansive defense of “older sources of morality, such as Scripture, family, and tradition,” reform opponents “reasserted the spiritual value of labor for children, especially boys” (114). That well-funded campaign attracted a national following of Americans who felt unmoored in postwar society. Together they defeated the Child Labor Amendment. Reformers would see partial victory with the 1938 Fair Labor Standards Act, which Wood treats briefly in an epilogue, but the opponents of reform won perhaps the bigger prize by fashioning a new moral argument against the regulation of capitalism that was now national in scope.Upon the Altar of Work is an exemplary work of intellectual and political history. Wood's skilled analysis closely tracks the arguments against child labor across decades with acute attention to both specific language and symbols and the wider context. That analysis perhaps necessarily focuses on elite subjects. Wood's story is not about how ordinary people, particularly child workers or their parents, interacted with debates over reform. Her work should be the point of departure for those much-needed studies. Upon the Altar will be of interest to scholars of labor, capitalism, reform movements, and the legacies of slavery in the United States.