Answer:
By proving that they're capable workers.
Step-by-step explanation:
In early 1900s, society mostly see women as incapable workers. So, the vast majority of the jobs were held by men only. During the world war 2, the vast majority of men were drafted as soldiers. This left a lot of jobs in the country left unfilled.
At that time, the women were the one that filled these jobs and became the backbone of United States' economy. They managed to silent all doubters from their high achievements.
Through this, women managed to opened up a lot of opportunities for employment.
After the world war 2 over, many companies started to hire more women knowing that they're just as capable. This highly contributed to the increase of women employment in 20th century.