As the graph shows, the average wage rose from $2.40 per hour in 1964 to $16.42 per hour in 2009.

BUT

$16.42 in 2009 had the same spending power as $2.40 did in 1964.—Inflation Calculator

So $16.42/hr in 2009 is really the same pay as $2.40/hr in 1964. 

Meanwhile, house prices have risen much faster than spending power.
A house costing $30,000 in 1975 cost $130,400 in 2002.—OFHEO  House Price Calculator

Dramatic 76% Percent Rise in Working Families That Spend Over Half of Their Income on Housing
"In just over half a decade the number of America’s working families paying more than 50 percent of their income for housing has grown 76 percent."

"Average annual work hours for women in married-couple families grew by a dramatic 93 percent between 1969 and 1996."—source  In 1976, 'housewives' outnumbered 'housewives with jobs' by 2 to 1. In 2002,  'housewives with jobs' outnumbered 'housewives'.—data  The number of wives earning more than their husbands has doubled since 1981.—data

Summary

The earnings needed to pay rent or mortgage has increased to more than 50% of income, so now mom works too instead of being at home with the children.

Conclusion

THE AMERICAN FAMILY IS ECONOMICALLY AND PSYCHOLOGICALLY WORSE OFF THAN IT WAS 30 YEARS AGO.

And yet mom & dad continue to dramatically increase their work output per hour: