 He served as the Georgia delegate to the United States Centennial Commission that planned and organized the country's Centennial celebrations and the International Exhibition of 1876.He was appointed to the Fulton County Superior Court by Governor Alfred H. Colquitt, serving from 1877-1883.In 1885 Hillyer served one term as mayor of Atlanta, during which time he became an expert on municipal water services, publishing several related articles and serving on the Atlanta Water Commission for many years.