Northwestern Terra Cotta Company was Chicago's largest manufacturer of architectural terra cotta. With headquarters at 1750 Wrightwood Avenue in Chicago, NWTC operated from ca. 1877 until its last factory, located in Denver, closed its doors in 1965. The firm was a leader in development of the architectural terra cotta industry and provided building elements for numerous Chicago buildings, including the Wrigley Building, Chicago Theatre, and Civic Opera House.
From the description of Northwestern Terra Cotta Company records, ca. 1880-1970. (Chicago History Museum). WorldCat record id: 713908111