Women have been the mainstay of the gruelling, seasonal canning industry for over a century. This book is a collective biography. Thousands of Mexicana and Mexican American women working in canneries in southern California established effective, democratic trade union locals run by local members. These rank-and-file activists skilfully managed union affairs, including negotiating such benefits as maternity leave, company-provided day care, and paid holidays -- in some cases better benefits than they enjoy today. The dramatic and turbulent history of their union is a major contribution to the new labour history.