With the arrival of the transcontinental railroad in the 1880s came the emergence of a modern and profoundly multicultural New Mexico. Native Americans, working-class Mexicans, elite Hispanos, and black and white newcomers all commingled and interacted in the territory in ways that had not been previously possible. But what did it mean to be white in this multiethnic milieu? And how did ideas of sexuality and racial supremacy shape ideas of citizenry...