Agrarian radicalism’s challenge to capitalism played a central role in working-class ideology while making third parties and protest movements a potent force in politics. Thomas Alter II follows three generations of German immigrants in Texas to examine the evolution of agrarian radicalism and the American and transnational ideas that influenced it. Otto Meitzen left Prussia for Texas in the wake of the failed 1848 Revolution. His son and grandson took part in decades-long activism with organizations from the Greenback Labor Party and the Grange to the Populist movement and Texas Socialist Party. As Alter tells their stories, he analyzes the southern wing of the era’s farmer-labor bloc and the parallel history of African American political struggle in Texas. Alliances with Mexican revolutionaries, Irish militants, and others shaped an international legacy of working-class radicalism that moved U.S. politics to the left. That legacy, in turn, pushed forward economic reform during the Progressive and New Deal eras. A rare look at the German roots of radicalism in Texas, Toward a Cooperative Commonwealth illuminates the labor movements and populist ideas that changed the nation’s course at a pivotal time in its history.