In 1900 Celedonio Mondragón and several other San Luis valley residents formed the Sociedad Protección Mútua de Trabajadores Unidos (SPMDTU) to help prevent the usurpation of Hispanic land ownership and to combat discrimination against wage laborers. The SPMDTU rapidly grew into a tristate organization with sixty-five local concilios (lodges) in New Mexico, Colorado, and Utah. Hispanic mutual aid societies proliferated at the turn of the twentieth century, providing such services as religious aid, burial funding, low-cost insurance, and fraternal support. The SPMDTU consolidated relief and support services and became a powerful force in helping families survive the transformations wrought by the influx of Anglos, the federal government, and new technologies. In the early twentieth century, the federal government became the primary welfare service provider for rural communities, but the SPMDTU has survived in the Southwest, continuing its traditions of fellowship and support.

Beginning with the social and economic conditions that gave rise to La Sociedad and culminating with its centennial anniversary in 2000, José Rivera examines the SPMDTU as a case study of collective action in the context of a pluralistic American society, rapid social change, and the dynamics of mobilization for cultural survival. Rivera's study explores the core values that have bonded SPMDTU members across generations and have sustained the organization for more than a century and addresses the question of whether or not La Sociedad will survive in the twenty-first century.