From March 1975 to March 2000, the labor force participation rate of mothers with children under age 18 rose from 47 percent to a peak of 73 percent, the U.S. Department of Labor's Bureau of Labor Statistics reported.
By 2004, the rate for these mothers had receded to 71 percent, where it remained through 2007.
In general, mothers with older children (6 to 17 years of age, none younger) are more likely to participate in the labor force than mothers with younger children (under 6 years of age).
This data is from the Current Population Survey and were collected in the March CPS. To find out more, see BLS Report 1011, Women in the Labor Force: A Databook (2008 Edition).