Why did the proportion of women working in clerical jobs increase during the progressive era?

The role of women reformers who were hired by the government agencies and ... For instance the number of “female clerical workers, for example, increased ... advancement of the age induced many more job opportunities during the era

The role of women reformers who were hired by the government agencies and  advancement of the age induced many more job opportunities during the Progressive Era.

a woodchuck would chuck 12.5 wood : 3

some american cities felt workers were being oppressed by business monopolies