In light of the recently published Common Core State Standards Initiative, public school curriculum has once again come under scrutiny. While curriculum debates have taken place since the very beginnings of public schooling in the United States, too few have taken more than a passing notice of the textbooks that, in many cases, comprise the majority of a classroom curriculum. This study examined the social values reflected in four reading textbooks popularly used in public schools in the United States in several historical eras of educational reform. Textbook content was sampled from "The New England Primer," "McGuffey Eclectic Readers," "The Silent Readers," and "Holt Basic Reading." Employing a methodology of qualitative content analysis, each textbook sample was examined for its reflection of social values, in particular those established by the Marshall, Mitchell and Wirt (1989) framework of social values: Liberty, Quality, Efficiency and Equity. Results of the study indicated that reading textbooks are value-laden and at least three of the social values of the Marshall, et al. (1989) framework often do appear in reading textbook content. The outstanding value of Liberty, rather than being reflected within a text, can most easily be seen in the social action that surrounds it. This study also provided additional evidence that the social values are cyclical in nature, as other scholars have suggested. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]