Casgrain led the women's suffrage movement in Quebec for twenty years. Her tenacity, her political contacts through her husband (who eventually became Speaker of the House of Commons), her leadership and her ability to inspire, all helped her to achieve her goal of women's right to vote in Quebec. She founded the Provincial Franchise Committee in 1921 and campaigned for women's rights, writing innumerable letters to influential people, making annual trips to the provincial capital at Quebec City, and broadcasts on radio, speaking for women's rights. From 1928 to 1942, she was the leader of the League for Women's Rights. She founded her own radio show in the 1930s, Fémina. Finally in 1938, she succeeded in having women's right to vote added to the platform of the Liberal Party of Quebec. The right was not won until 1940.
