Stevens became active in the trade unions, notably as one of the leaders of the Knights of Labor in Chicago. In 1877, she organized the Working Woman's Union, No. 1, of Chicago, and was its first president. Removing from that city to Toledo, Ohio, she threw herself into the movement there and was soon one of the leading forces of the Knights of Labor. She was again instrumental in organizing a woman's society, the Joan of Arc Assembly Knights of Labor, and was its first master workman and a delegate from that body to the district assembly. In the district, she was zealous and energetic, serving as a member of the executive board, organizer, judge, and for a number of years, recording and financial secretary. In 1890, she was elected district master workman, becoming the chief officer of a district of 22 local assemblies of knights. She represented the district in the general assemblies of the order in the conventions held in Atlanta, Georgia, Denver, Colorado, Indianapolis, Indiana, and Toledo, Ohio.