We describe patterns in the composition of American-citizen doctorate recipients from the early 1960s to 2000. The propensity of bachelor’s degree recipients to earn PhDs varied widely during the 1960s and 1970s, especially for men, but has been relatively constant since the early 1980s. PhD propensity varies widely across students from different types of BA institutions, with higher propensities among those attending research universities and selective liberal-arts colleges. The share of PhDs awarded to women increased dramatically over the past 40 years and was driven largely by increases in the number of women earning BAs.