On January 21, 1875, she testified before the Indiana General Assembly, presenting 21,050 signatures on temperance petitions from forty-seven Indiana counties. Many of the legislators showed "open contempt" as Wallace spoke, and afterwards she credited the event for prompting her to become a suffragist. Later that year she attended the national WCTU conference in Cincinnati, Ohio, where the delegates approved her proposed resolution for a national vote of men and women on prohibition of the manufacture and sale of alcoholic beverages.