On January 23, 1880, Wallace was one of several who testified before the U.S. Senate Committee on the Judiciary on women's right to vote. As she explained in her address, "You must admit that in popular government the ballot is the most potent means of all moral and social reforms." In 1881 Wallace was among those who lobbied the Indiana General Assembly to approve a woman's suffrage amendment to the state's constitution. The state legislature voted in favor of the suffrage amendment and a prohibition provision in 1881; however, at that time Indiana law required passage in two consecutive sessions of the general assembly followed by approval from the state's voters before the legislation could become state law. At the next legislative session in 1883, the Indiana House of Representatives approved the woman suffrage resolution by a 53 to 42 vote, but the Indiana Senate refused to act on it. The Indiana legislature took no further action on woman suffrage until 1920, when it ratified the Nineteenth Amendment to the U.S. Constitution.