 In 1879 he returned to Minnesota, where he was Superintendent of Public Schools from 1879 to 1881 and again from 1883 to 1885.He also served as the secretary of the Winona Board of Trade from 1878 to 1885, secretary of the St. Paul Chamber of Commerce from 1886 to 1887, and secretary of the Duluth Chamber of Commerce from 1887 to 1890.Phelps was president of the American Normal School Association from 1856 to 1900, president of the National Educational Association from 1875 to 1876, and vice-president of the first International Conference of Educators, over which he presided at the centennial exposition in 1876.