Concerns about both the content and lack of focus of the U.S. mathematics and science curriculum, both as it is stated in state-level curricular frameworks and how it is implemented in the classroom, have appeared in major studies since the early 1980s (National Center for Education Statistics [NCES], 2000a). In 1983, the National Commission on Excellence in Education (NCEE) concluded in A Nation at Risk (NAR) that the curricular “smorgasbord” then offered in American schools, combined with extensive student choice, explained a great deal of the low performance of U.S. students (NCEE, 1983, p. 18). Since the publication of NAR 20 years ago, most states have increased the number of mathematics and science courses required for high school graduation as a way to address this concern and many have instituted one form or another of high-stakes testing to build student, teacher, and school-level accountability into the equation. Furthermore, a number of states and districts have also implemented “systemic” or “standards-based” reform efforts to align curricular content with student testing and teacher professional development. Although these are by no means the only reforms undertaken in the last quarter century, they are examined here because of their explicit mention in NAR and because of their direct impact on the content of the math and science curriculum.