"To be sure, changes in American family structure have been fairly continuous since the first European settlements, but today thesechanges seem to be occurring so rapidly that the shift is no longer a simple extension of long-term trends. We have passed a genuine watershed: this is the first time in our history that the typical school-age child has a mother who works outside the home."
--
Source : Kenneth Keniston (1977). “All Our Children: The American Family Under Pressure”, Harcourt on Demand