Tore C. Olsson's Agrarian Crossings exemplifies how history can give new meaning to the past by looking at the landscape of history from a different perspective. Olsson retraces the evolution of agrarian policies pursued in the United States and Mexico between the early 1930s and the Cold War's beginning. The 1930s and 1940s saw the emergence in both countries of radical approaches to their agrarian strains. In the United States, Franklin D. Roosevelt, elected on a platform that promised to address the 1929 economic crisis through state intervention, launched a campaign to revitalize southern agricultural production while relieving the social and economic conditions of local sharecroppers. In Mexico, President Lázaro Cárdenas reignited radical agrarianism, which brought expropriations of large landholdings and redistribution of 50 million acres of land, a vast majority among poor farmers who worked in communal parcels (ejidos). These processes, which had extraordinary social, political, and economic consequences in both countries, have long attracted historians' attention. What makes Agrarian Crossings original against this backdrop is its methodological choice to ignore the Mexican-US border and adopt a wider spatial scale that identifies the agrarian policies pursued by Cárdenas and Roosevelt as interconnected strategies, aimed at fixing similar problems. This approach considers the agrarian New Deal and Cárdenas's radical agrarianism to be two parts of the same historical process.Beginning in the late 1870s, both Mexico and the US South experienced dramatic transformations of their rural landscapes that, following the reckless expansion of commercial agriculture, dispossessed of their land yeomen and peasants in both countries. In the 1930s, the Lázaro Cárdenas government moved to address rural poverty through an aggressive program of expropriation and redistribution of hacienda lands, offering active, material support to poor campesinos. Through an approach that transcends artificial national borders, Olsson shows the influence that this radicalism unfolding in Mexico exerted over agrarian New Dealers in the United States, who came to see Mexico's solutions as applicable to the problems of US southern agriculture. A group of US southern liberals blamed their region's lack of agricultural dynamism on an inefficient, socially unjust production regime. The solution was a federal program that redistributed land, limited plantation owners, and empowered poor sharecroppers as Cárdenas had done in Mexico. As the Roosevelt administration developed more radical antipoverty policies after the 1936 elections, these ideas became formalized under the Bankhead-Jones Farm Tenant Act. This created the Farm Security Administration (FSA), which, in Olsson's words, converted “thousands of tenants and sharecroppers into small landowners, and endowed them with credit and basic technologies” (p. 56). This is only one example of what Olsson describes as a constant pilgrimage of New Deal bureaucrats to Cárdenas's Mexico for inspiration.The second part of Olsson's book turns to how ideas and paradigms for state-led rural reforms likewise flowed from north to south. Olsson shows how Mexican agricultural economists became deeply familiar with New Deal agrarian policies. Specific agronomists traveled to the United States to learn, and more generally the Cárdenas administration sought to replicate the FSA's technical programs among the ejidos' campesinos.Olsson's first chapters have important implications for the broader historiographical debate over twentieth-century inter-American relations, offering a more nuanced vision of the political and ideological interactions between Latin America and the United States. Agrarian Crossings shows that, for at least 20 years, Mexican radicalism did not clash with Washington's foreign policy but actually echoed agrarian New Dealers. In this sense, Olsson's book shows that, at least for Mexico, Roosevelt's Good Neighbor diplomacy was based not just on pragmatism but on ideological convergence. Rather than stressing continuity in inter-American relations, Agrarian Crossings raises the question of why and how the Cold War ended an extraordinary era of radical cooperation.The last part of Olsson's book challenges the common understanding of the Green Revolution. In 1943 Cárdenas's successor, Manuel Ávila Camacho, signed a cooperation agreement with the Rockefeller Foundation, which led to the Mexican Agricultural Program (MAP), the basis for a larger Washington program to increase Third World agricultural productivity and thus prevent social instability during the Cold War. While scholars have strongly questioned Green Revolution policies in the Third World, Olsson shows that the Rockefeller Foundation, in its project's first stages, “displayed a surprising sensitivity to the ejido farmers,” planning a “research program tailored to the economic limitations of smallholders” in Mexico rather than solely boosting agricultural productivity (p. 144). This socially conscious approach, drawing from experiences in the US South, was evident in the decision to distribute among Mexican peasants synthetic corn seeds rather than double-cross hybrid ones, which meant that “farmers could nearly match the yields of their double-cross-hybrid-planting neighbors, but without having to annually repurchase seed, thus preserving both their autonomy and pocketbook” (p. 142).Such sensitivity ended with the election of Miguel Alemán. His decision to focus on agricultural productivity rather than redistribution mirrored how radical agrarian New Dealers were marginalized in the United States by more conservative policymakers. Olsson's interpretation of Alemán's agrarian policies is probably the book's least persuasive part. This shift in agrarian policies followed Alemán's decision to launch an aggressive plan of industrialization, which goes almost unnoted by Olsson. Commercial agriculture was needed to increase exports and generate hard currency for importing the capital stock needed for industrialization, which since at least the late 1920s was associated not with conservatism but with progressive internal social transformation and strengthened national sovereignty. Thus the transformations in agrarian policies that Alemán's approach to industrialization entailed represented something more complex than a mere conservative turn.This minor objection aside, Olsson has successfully produced an extremely original, solid, and convincing book. Agrarian Crossings breaks artificial borders by retracing the powerful interconnections and mutual influences of apparently autonomous and separate historical processes, adding in the process to our understanding of both Mexican radical agrarianism and Roosevelt's New Deal. In addition, this detailed study of entangled and converging radical agrarian policies in 1930s and 1940s Mexico and the United States adds nuance to how we view the evolution of inter-American relations.