In 1853, the most important man in nineteenth-century American education gave a speech praising female teachers. Horace Mann was the head of the growing common school system in Massachusetts, where women teachers already outnumbered men by four to one. That helped save money for taxpayers, because school districts could pay women less than their male counterparts. It also capitalized on women’s natural instincts and abilities, Mann argued, converting America’s formerly chaotic, male-led classrooms into domiciles of love and order. “How divinely does she come,” he declared, extolling the female teacher,

her head encircled with a halo of heavenly light, her feet sweetening the earth on which she treads, and the celestial radiance of her benignity making vice begin its work of repentance through very envy of the beauty of virtue!

In a rapidly industrializing nation, in which there were many perils of poverty and violence, as well as opportunity, schools needed to inculcate thrift, civility, and self-control in the young. And the most obvious candidates to provide this instruction were women, whose delicate constitutions prevented them from pursuing other kinds of work outside the home.

The same year, in an adjacent state, the most important woman in nineteenth-century American politics gave a speech denouncing men like Horace Mann. Susan B. Anthony had taught school for over a decade but had become tired of its deadening routines; she also resented the nineteen-year-old man who was hired to supervise her, at a higher salary than she could hope to earn. In her first recorded public address, to the New York State Teachers’ Association, Anthony argued that the profession would never achieve parity with others if men continued to regard it as a feminine domain:

Do you not see that so long as society says a woman is incompetent to be a lawyer, minister, or doctor, but has ample ability to be a teacher, that every man of you who chooses this profession tacitly acknowledges that he has no more brains than a woman?

Anthony asked the association’s male-only leaders: “And this, too, is the reason that teaching is a less lucrative position, as here men must compete with the cheap labor of women?” Privately, Anthony’s feminist comrade Elizabeth Cady Stanton condemned “schoolmarms” who had attended specialized “normal schools” for teachers—not the more demanding liberal arts colleges, which were starting to open their doors to women. The normal schools were also a brainchild of Mann and others of his generation. Teachers who defended the second-rate teacher-training institutions they had attended were “an infernal set of fools,” Stanton told Anthony. Indeed, Stanton concluded, the entire teaching profession was…