In recent decades, the number of families headed by women has increased dramatically. In this article, we use U.S. census data from 1950 to 1980 to consider the extent to which population growth, fertility change, decreased marriage, increased divorce, and increased household headship have contributed to the growth of femaleheaded families. For white women, the major source of growth during the 1960s and 1970s was an increase in the number of formerly married mothers due to increased divorce and decreased remarriage. There is a similar pattern for black women for the 1960–1970 period. During the 1970–1980 decade, however, the major source of growth for black women was an increase in the number of never-married mothers due to decreased marriage and increased fertility among nonmarried women.