At no time in history did pants embody the struggle for power more than during the French Revolution. Basically, the French Revolution is the main reason your pants go down to your feet.
If you've had to study the French Revolution, you know that it was actually more like several revolutions rolled into one, with leaders coming and going so fast that it was hard to keep track of all the heads rolling. But throughout the Revolution, it was the Sans-culottes who did most of the dirty work. The Sans-culottes were a group of working class militants who came to symbolize the revolutionary spirit in France ... and their name literally translates to "without breeches."
As in "that guy on the floor is a huge sans culottes."
This does not mean they fought in the nude. The name was actually a roundabout, somewhat misleading way of saying that the revolutionaries wore long pants, as opposed to the knee-length ones worn by the Royalists.
"Unhand me, you full-panted beast!"
Soon, the Sans-culottes became a symbol of freedom and patriotism -- as did their trousers. After the Revolution, long pants were worn by men of all social strata as a sign of compliance with the new government. The art world started reflecting their popularity, painting the Sans-culottes as ordinary men willing to risk their lives for liberty.
Albeit in a casual, indifferent way.
The artwork depicting heroic soldiers in long pants influenced the kinds of idealized political posters and advertisements we see today. The image of the Sans-culottes has become so ingrained in the modern consciousness that trousers that go down to your shoes are still the only acceptable way for men to wear them. The Sans-culottes effectively erased the manliness of the knee-length breeches (baseball players notwithstanding).
Sans-Culottes established fashion (and more specifically, pants) as a legitimate form of patriotism. So the next time you see a guy wearing a pair of American flag pants, let him know that he has the French to thank for them.
We're sure he'll be thrilled to hear it.
By the 20th century, pants were firmly established as a symbol of power. If you think that's bullshit, consider some of the phrases we use every day: "Keeping your pants on" means being in control of yourself. "Wearing the pants in a relationship" means being the boss.
"That skirt means your mother doesn't get to leave the house until I've had enough goddamn pancakes."
But, throughout all of these upheavals in the name of trousers, there was one group that was still unable to access them: women. One hundred years ago, it was still extremely unusual for a woman to wear pants. Or vote, or go to college, or get paid as much as a man (we're still working on that one). For centuries, a woman's powerlessness was signified by the clothes she wore. In 1919, women had finally won the right to vote in the U.S. ... but it was still completely taboo for them to wear trousers.
"Sure, you can decide the future of the nation, but don't go getting any crazy ideas."
By the 1930s, starlets like Katherine Hepburn and Marlene Dietrich openly wore pants for comfort and style, but this wasn't really an option for most women. It was the 1930s equivalent of Lady Gaga wearing a meat dress or something. Except crazier. Outside of a few brave souls, women continued to stay away from pants. The taboo was strong enough that nothing short of a worldwide war would change it.
Fortunately, it was the 1930s.
"What's this about Germany ...?"
World War II changed everything. When women entered the workforce, they did so in their husband's pants. Pants were once again seen as a symbol of patriotism, this time in the form of sacrificing silk dresses so the men could have parachutes. When the war was over most women went back to wearing dresses, but trousers became increasingly associated with working women and the Feminist Movement.
It wasn't until the 1970s that pants became a fully accepted choice for women. One major factor was Title IX, which prohibited educational institutions from discriminating on the basis of sex, meaning that colleges could no longer kick women out for wearing pants.
How could kids possibly concentrate with this waving around in their faces?
In the same year (1972), Helen Reddy recorded the song "I Am Woman, Hear Me Roar," which became a rallying cry for second wave feminists. Reddy became an icon and regularly stood toe-to-toe with the men in an ultra-hip pair of trousers. She was so devoted to pants that she even changed history by appearing as a woman sporting bell bottoms in 19th century Maine in Disney's Peter Dragon.
Her character was secretly a time traveler.
But despite the ridiculousness of the image, these trousers signified that Reddy's character was a tough, independent woman. The same was happening all over the world. Pants had come full circle as a power symbol that once gave men a convenient way to exaggerate the size of their dicks.
Seriously, pants should have their own holiday. Or at least some kind of monument or something.
For more unusual world-changers, check out 6 Mistranslations That Changed The World and 5 Horrible Diseases That Changed The World (For the Better).