Civil War Arsenal
Here is a cover of Harper's Weekly in July 1861 with what is the best known image of women working in arsenals - here, cartridge fillers at the Watertown Arsenal in Massachussetts.
In her wonderful book "Army at Home: Women and the Civil War on the Northern Homefront", Judith Giesberg analyzes this image. In it, there is nothing at all unseemly about working women. These women appear to be nicely dressed and under close male supervision. However, the male supervisors at this same arsenal would, in 1864, be accused of sexual harassment and favoritism by some of its female employees.