Which law has led to a 40% increase employment for women

The Defense of Marriage Act.

WW2

Explanation: at the height of the war, women comprised 4% of skills works. In 1944, skilled female workers made an average weekly wage of $31.21 while skilled meal workers and a 54.65 weekly from 19:40 to 9 1044, the percentage of women workers employed in factories increase from 20 to 30%