Advocacy to encourage women to enter male-dominated trades has a long history, though leadership in this sphere of activism has rarely been documented in feminist histories. Efforts to improve women's working lives have most often focused on facilitating women's entry into the professions, company boards or upper management, and on campaigns to secure equal pay for work of equal value. Throughout the 20th century, however, numbers of women have promoted women's entry into skilled, working-class jobs that were thought to be the natural domain of men. One important reason for questioning the high levels of gender segregation in these trades and encouraging women to enter them has been the recognition that men's social power was bolstered by their claim that they had a special relationship with technologies. The need to expand women's opportunities into trade employment was also linked to key feminist goals of eliminating gender wage inequality and enhancing women's employment choices. Male-dominated trades promised employment that was better paid and more highly valued than female trades and often opened up opportunities for interesting work, independence and mobility that were unusual for working-class women.