Episodes of labor-saving technological change and rural–urban migration have become universal patterns of economic development the world over. Donald Holley, in The Second Great Emancipation, sets out to tell the story of the last great episode of such change in the United States, when the cotton harvest was mechanized following World War II. The last major crop to make the transition from hand production, cotton was extraordinarily labor-intensive, especially the harvest. In 1945 millions of workers hand picked almost every boll of American cotton, but by 1970 farmers gathered their crop with John Deere and International Harvester mechanical cotton pickers. Folks, mainly blacks, who had for generations performed one of the most backbreaking forms of stoop labor, moved to northern and western cities. As Holley tells it, the First Great Emancipation occurred when President Lincoln freed the slaves and the Second Great Emancipation when the mechanical cotton harvester freed laborers from the drudgery of the cotton harvest, poverty, and Jim Crow discrimination, and southern producers from inefficient production methods and farm sizes. It is a really big and important story of profound technological and demographic changes with spillover effects into civil rights, racial economic equality, and politics. These events, for example, transformed race from a southern regional to a national issue.