Monitoring the Future is a long-term program of research being conducted at the University of Michigan's Institute for Social Research under a series of investigator-initiated research grants from the National Institute on Drug Abuse. Now in its 34th year, the study is comprised of several ongoing series of annual surveys of nationally representative samples of 8th- and 10th-grade students (begun in 1991), 12th-grade students (begun in 1975), and adults (begun in 1976). As the authors report in this volume, several segments of the adult population are covered in the follow-up surveys of high school graduates. One important segment is American college students; a second is their age peers who are not attending college, sometimes called the "forgotten half"; and a third is all young adult high school graduates of modal ages 19 to 30, which are referred to as the "young adult" sample. Finally, high school graduates at the specific modal ages of 35, 40, 45, and 50 are included each year in longer term follow-ups. The follow-up surveys have been conducted by mail on representative subsamples of the previous participants from each high school senior class. The present volume presents data from the 1977 through 2008 follow-up surveys of the graduating high school classes of 1976 through 2007 as these respondents have progressed into adulthood--now through age 50 for the oldest respondents. (Contains 30 tables, 74 figures, and 61 footnotes.) [This content was produced by the Monitoring the Future project at the Institute for Social Research, University of Michigan. For Volume I, see ED508295.]