Academic achievement in American high schools is increasingly defined in terms of quantifiable values. Despite being designed to produce favorable data, explicit standardized-test preparation has an insignificant impact on scores and is counterproductive to the cultivation of attributes necessary for success in higher education and effective civic engagement. Reaffirming trends known since the 1970s, standardized test scores directly correlate to socioeconomic status (SES) across time and space, as this study of six Illinois high schools demonstrates. SES functions to engender test scores independent of curriculum decisions and to a higher degree than racial/ethnic demographics alone. Educational inequality cannot be addressed without broader systemic changes to the American political economy. To implement such changes, it is incumbent upon teachers to transcend class-specific curriculums, foster the imagining of different social realities, and develop students' propensity for collective action through critical pedagogy.