Recent research shows that U.S. 15-year-olds are behind their international counterparts in problem solving and mathematics literacy, ranking 24th of 29 nations (Lemke et al. 2004). Therefore, a key concern among policymakers and educators is improving the quantitative and analytical skills of American youth, who face job prospects in an economy that increasingly values a strong foundation in mathematics and science. As a means to improve proficiency in this area, many states have increased their course requirements for graduation. This study, which uses data from the Education Longitudinal Study of 2002 (ELS:2002), improves upon past research by using information from high school transcripts to identify the exact course sequences students take and links them with achievement test scores that have been scaled to indicate different levels of mathematics proficiency. This linkage provides a more detailed understanding of the curricular pathways students travel and the types of proficiencies they acquire along the way. Chapter 1 provides a brief background description of the pattern of mathematics coursetaking in the United States and lists the research questions. Chapter 2 describes the ELS:2002 data and the measures used in the analysis. Chapter 3 provides the results of the analysis. Chapter 4 concludes with a discussion of the findings and their limitations. Appended are: (1) Technical Notes and Glossary; and (2) Standard Error Tables for Estimated Means and Proportions, with Weighted Standard Deviations and Raw Sample Sizes for Means. (Contains 32 tables.)