Background/Context: For more than a century, standardized achievement tests have been a feature of American education. Throughout that time, critics of standardized tests have argued that their use has detrimental effects on students, schools, and curriculum. Despite these critiques, the number and uses of standardized tests have increased steadily. Though a great deal of research has focused on the technical design of tests, the history of individual tests, and general critiques of testing, there is little research that helps explain the continued use of standardized tests in American education despite near constant criticism. Purpose/Objective/Research Question/Focus of Study: This article develops a framework for understanding a basic paradox in the history of standardized testing in American education: the durability of standardized testing in the face of persistent criticism. Seeking to address this paradox, the article asks why tests have persisted and proliferated even though students dislike taking tests, educators believe that tests distort the learning process, and experts challenge the validity of test results. Research Design: This article involves a historical analysis of structural and cultural aspects of American education that help explain the particular uses and durability of testing. Conclusions/Recommendations: First, we identify three master critiques of standardized tests: distortion, waste, and misclassification. We find that, despite these persistent critiques, four important contextual features of the American education system help explain the continuous hold that standardized tests have had on American education: that the American education system is decentralized, avowedly meritocratic, publicly funded, and central to aspirations of upward mobility. These contextual factors, along with the historically contingent development of testing expertise, testing culture, and development of testing infrastructure, provide a framework for understanding the persistence of testing. Together, these factors create a dynamic system in which critiques of tests lead not to the elimination of testing, but to its further elaboration and evolution.