During four periods of forty to fifty years each, a distinctly “American” family system emerged with vigor. Its characteristics were: early and nearly universal marriage; high fertility; close attention to the rearing of children; complementary roles between men and women in their tasks as husbands and wives; flexible intergenerational bonds; aspirations toward forms of self-sufficiency; and structural stability. Such attributes differed from those found in the “European” model also evident after 1700, featuring late marriage, a high proportion of adults never married, and significantly lower fertility.