T H E P A S T 20 years have seen a rapid increase in the number of stepfamilies due to the increase in the divorce rate in the United States. Although the divorce rate is high, people appear to value the institution of marriage, but with a series of partners. The divorce rate for second and subsequent marriages is higher than for first marriages and has been partially attributed to the presence of children from previous relationships (Bumpass, Sweet, 8c Castro-Martin, 1990; Glick, 1989). This chapter presents results from the Developmental Issues in StepFamilies (DIS) Research Project, which investigated the longitudinal impact of divorce and remarriage on children's social, emotional, and cognitive development (Bray, 1988b; Bray 8c Berger, 1993a).