John G. Ralston designed 4 of the Carnegie libraries: Waterloo East (1902), Waterloo West (1902), Nashua (1905), and Traer (1914).
John Glen Ralston (1870-1956) was born in Vinton, Iowa. In 1890, he attended the Tilford Academy in Vinton for a one-year course. From 1890 to 1897, Ralston worked as a carpenter in Vinton for the architectural firm of Murphy and Wallace, and he completed a course in architecture from the International Correspondence School of Scranton, Pennsylvania. In 1897, Ralston moved to Waterloo and entered into the partnership of Murphy and Ralston, which lasted until Murphy’s death in 1904. Ralston designed commercial and institutional buildings, as well as residences. He had also received the first commission for the Carnegie library in Grundy Center. Ralston practiced until his eighty-third year, and he died in Waterloo.
Ralston designed the four Carnegie buildings in a variety of styles. The Waterloo East building was in the Neoclassical style with Bedford stone, and it shared stylistic similarities with Ottumwa (1901), the third Carnegie grant in Iowa. Both buildings featured elements from classical triumphal arches for their entrances; Waterloo East also included a raised barrel vault ceiling over the central part of the building with a thermal window capped by a parapet above the doorway. (The thermal window and elaborate parapet over the entrance was copied for the Iowa Falls (1905) library). The Waterloo West building was also designed in the Neoclassical style but it was built of brick with accents of stone. Here Ralston created a projecting pedimented porch flanked by Ionic fluted columns for the main entrance. The design for Nashua made reference to the Gothic Revival movement with the strong pointed gable over the front entrance and the embellishment of flat crenellations on the arch and on the four corners of the building. Traer was designed in the Renaissance Revival style with a cornice that conceals the roof that is broken by a pediment over the front entrance that is flanked by two pairs of brick pilasters. No plans for these four buildings have yet been found.
 Wesley I. Shank. Iowa’s Historic Architects: A Biographical Dictionary, (Iowa City, IA: University of Iowa Press, 1999), p. 134-136