This study examined the relations among family structure, caregiver relationship history, aspects of environmental adversity, and teacher reports about the externalizing behaviors of 6- and 7-year-old children from economically disadvantaged families. Family structure contrasted intact families, stepfamilies, single-parent families, and cohabiting families. Problem behaviors were more frequent for children from unmarried families than from married families and were more frequent for boys than for girls from cohabiting families. Relationship history reduced the effects for family structure. Children's adjustment varied with both the current status and past stability of caregiver intimate relationships for disadvantaged families.