This biography traces the life of Manitoban Beatrice Alice Brigden (b.1888 - d.1977) from her early childhood to her mid-forties (1932), when she was a recognized political and social activist and an executive member of the newly formed political party, the Co-operative Commonwealth Federation. Based on her extensive collection of personal journals, work-related correspondence and political writing, this thesis examines aspects of Brigden's personal life and experience, to identify important influences, understand her motivation and perspective. It identifies traits she held in common with many of her contemporary social reformers and suggests that much of Brigden's life fits the familiar pattern taken by many men and women - that of moving from religious reform within the church, to social reform, to political reform. By presenting personal details, the biography adds to our understanding of the ordinary lives of young girls and women in Manitoba in the early decades of the twentieth century. It also examines Brigden's rather unusual career as a "social purity worker" to explore both the practical reality of the job and its influence on her political development. Finally, it offers insight into the attitudes of similar women active in some of the social and political reform movements of the time; insight which requires an examination of formative years, not merely the reconstruction of a successful adult career. Brigden was active in, or at least witnessed many important historical developments in western Canada in the 1910's - 1930's; the Winnipeg and Brandon General Strikes, the Labor Church movement and the birth of the CCF. She also organized two grassroots groups focusing raising political awareness and the participation of women in the political process, the People's Forum Speakers Bureau and the Labor Women's Social and Economic Conference. Brigden's gender is as much a part of her story as her religious and ethnic background and their influence on her choices is discussed. Her biography also sheds light on women's role in grassroots organizations, specifically those devoted to social and political reform. While offering some answers to the question of what makes a reformer, this thesis ultimately suggests that Brigden's high level of participation and involvement in politics may not be unusual for women, but previously overlooked and undervalued by earlier historians.