Courtney G. Joslin.
Families are changing. In the past, most adults in the U.S. were married, and almost all children were born to married persons. That is no longer the case. About half of all adults in the U.S. today are unmarried. Being unmarried, however, does not necessarily mean that the person lacks a family. As marriage rates have declined, cohabitation rates have increased. Today there are approximately 18 million adults in the U.S. who are living with nonmarital partners. These trends are likely to continue.