The purpose of this dissertation was to analyze the content of textbooks used in undergraduate survey courses in interdisciplinary humanities to understand the content of the curriculum and how an author's viewpoint shapes the product. By enumerating the texts and images authors and their publishers used to illustrate 20th century culture and the transition into the 21st century, the analysis generated a description of the range of perspectives from traditional to postmodern found in six sampled textbooks. Textbook content provided chronological data, while authors' source citations established identity properties of the works' contributors. Through a ranking system of authors' treatment of content and citations, the most traditional perspectives were compared to the most postmodern. Classifying cultural contributors by identity properties gave a quantitative rate of inclusion of traditionally excluded groups. A trend of increase in "diversity-infusion" was observed among all authors when the content of the textbooks was compared in chronological sequence. The qualitative differences, as constructed for this dissertation, indicate that each textbook constitutes a varied and unique representation of author perspective. The project's contribution to future research is the development of a database of art works and literary sources from the years 1900-2006 that can be used for quantification and for further study.