Deyo was one of the delegates of the Universal Peace Union to the International Peace Congress and the Exposition Universelle of 1889, and did some effective work in the peace cause. Her address to the congress was printed and distributed at the Exposition. She was also present and presented a paper in the Woman's Rights Congress in Paris. She represented the union in the Woman's Council held in Washington, D. C. in March, 1888, and signalized the occasion by calling a grand peace meeting in the Church of Our Father, where many prominent women made addresses. In addition to her work in the ministry, preaching three times each Sunfsy and attending funerals and weddings, she was an active worker in the temperance and prohibition cause, and at one time, traveled and lectured for that interest and organized its work. However, her greatest efforts were made towards substituting peace for war and harmonizing the difficulties constantly arising in families, neighborhoods and churches. By her efforts and those of her husband, the Dutchess County Peace Society, one of the large and flourishing branches of the Universal Peace Union, was organized in 1875 and kept active by them until her ministerial duties made it necessary to turn over the work to others.