A history of European immigrants in Texas and how they redefined racial identity. While the creation of a Black-White racial binary was foundational to most of the United States, nineteenth-century Texas developed a unique tripartite system that acknowledged the role of individuals of Mexican ancestry in a region that was Spanish, Mexican, and an independent nation before becoming a US (and briefly Confederate) state. Yet this framework was fraught, struggling to accommodate new arrivals from beyond North America, in particular the Irish, Germans, and Czechs. Texan Crucible tells the story of these immigrants and how they became Anglo. Marian Barber reveals the ways language, religion, alcohol use, and attitudes toward slavery distinguished these newcomers to Texas from those arriving from the eastern United States and how they nevertheless created thriving, influential communities. Their status was shaped by events inside and far beyond Texas, including an 1887 prohibition fight, the Civil War, and two world wars that encouraged them to erase their distinctiveness. As segregation was formally outlawed and civil rights activism grew, understandings of race shifted, cementing these groups' status as Anglo. Texan Crucible recovers the histories of German, Irish, and Czech immigrants and unveils the social construction of racial difference underpinning Texan identity.