I was doing a little research on just when women started wearing trousers (pants on this side of the pond) and came across this article at Britannica.com.

The last paragraph is precious. "Today in the US, the question of whether women can wear pants in public isn't a question at all, which means we're free to move on to the next frontier of gendered fashion, making it socially acceptable for men to wear dresses. Fair's fair, right?"

britannica.com
History of American women wearing pants
3–4 minutes

SPEAKER 1: It's strange to think about today, but there was a time in the United States when women just didn't wear pants. In many cultures, women wearing some kind of trouser is an ancient phenomenon, but in the United States there was a time when women were expected to limit their options to skirts and dresses, especially out in public. So when and how did this change? When did women start wearing pants?

Well, first, let's be clear that some women have sometimes worn pants in America for centuries. Women sometimes wore pants for work or leisure, even in the 19th century, though society didn't always look kindly on these practical clothing decisions.

The long skirts women wore were often bulky and heavy. These clothes were both socially and physically restrictive. They got in the way when women wanted to enjoy a full range of motion.

The dress reform movement arose in the mid 19th century with the goal of giving women the freedom to wear trousers for both practical and political purposes. Trousers were seen as a symbol of women's rights, a radical proposition at the time.

It was around 1851 that a woman named Elizabeth Smith Miller designed an outfit that would become iconic among believers in the concept of what was called rational dress for women. It consisted of a skirt and loose trousers with a short jacket on top. The design was championed by Amelia Jenks Bloomer, and they quickly became known as bloomers. Bloomers eventually fell out of fashion, but the name lives on as a description for various baggy, divided garments for the lower body.

Still, as the popularity of bloomers faded, pants became, once again, something women generally wore only in private or for sporting activities. It would take big changes to finally bring women's pants into the mainstream, and those changes came with two world wars.

During the First World War, the mobilization of men in the army meant that women began doing jobs that had previously been reserved for men and sometimes wearing the pants that went with them. But it was during World War II that women in both civilian and military life began wearing pants in large numbers, not just for work, but socially, too. It's hard to imagine the Rosie the Riveter wearing a skirt below that famous raised bicep.

After the war, many women continued to wear pants, but women's fashion still tended to focus on skirts and dresses. But more than a century after women's rights activists had first begun their push to reform how women dress, the women's liberation movement of the 1960s and 1970s finally helped to break down the stigma against women wearing pants.

Today in the US, the question of whether women can wear pants in public isn't a question at all, which means we're free to move on to the next frontier of gendered fashion, making it socially acceptable for men to wear dresses. Fair's fair, right?