However well-placed you may be now, times may come when you will have to know how to milk, cook, cut wood, wash clothes, act as a nurse, or even defend your own life. Many things which are now done for you will have to be done without any assistance from others. All these things you can learn as a Girl Scout.

— “How Girls Can Help Their Country: Handbook for Girl Scouts,” published 1913.

* * *

It might be an overstatement to say that the Girl Scouts shaped American girlhood. Social movements collide and entwine — Title IX, Barbie, Susan B. Anthony, Miley Cyrus — and it’s nearly impossible to measure the cause and effect of each one. But it would be fair to say that the Girl Scouts have reflected American girlhood, that they have charted the history of what it has meant to be young and female, especially young and female and industrious and outdoorsy.

They are turning 100 this month. There will be a singalong on the Mall this summer, which 200,000 Girl Scouts are expected to attend. Across the world, girls glued to YouTube instructional videos are already practicing the jazz hands that accompany the official theme song of the event, “Ignite.” Guinness record keepers will be on hand for a head count; the Scouts are trying for the largest flash mob in history.

In recent weeks, conservative groups have accused the nonpartisan organization of being a “radicalizing” force, promoting abortion and homosexuality. A teenage California Girl Scout identifying herself as Taylor spoke out angrily after learning that a Colorado troop had decided to admit a transgender child who self-identified as female.

She called for a ban on the cookies.

Girl Scouts are often reduced to their cookies in ways that Boy Scouts are never reduced to their popcorn. The Girl Scouts must walk the tightrope of being too old-fashioned for some and too progressive for others. Debates and discussions have less to do with what a troop is doing in Colorado and more with the bigger things we are always discussing, the issues we are always worrying about: What do we want our girls to be? How will they affect the nation they will inherit?

Underlying discussions of just what the Girl Scouts are up to is surely this realization: 10 million girls from 145 countries — the total number of Girl Scouts worldwide — have a really loud voice.

* * *

HOW TO SECURE A BURGLAR WITH EIGHT INCHES OF CORD: Make a slipknot at each end of your cord. Tie the burglar’s hands behind him by passing each loop over his little fingers. Place him face downwards, and bend his knees. Pass both feet under the string and he will not be able to get away.

— “How Girls Can Help Their Country,” 1913.

* * *

“In 1912, women didn’t even have the right to vote,” says Lidia Soto-Harmon, the chief executive of the Girl Scout Council of the Nation’s Capital. “And here the Girl Scouts were saying that girls needed to learn how to camp.”

She shares a few historical tidbits.

The Girl Scouts were the first women to march in an inaugural parade, for Woodrow Wilson.

The Girl Scouts used to play basketball in their bloomers, covering the windows of the gymnasium with blankets so they wouldn’t shock the community.

Founder Juliette Low was championing disability rights when disabled people were hidden from public view; the Rev. Martin Luther King Jr. called Girl Scouts a “force for desegregation” back in 1956, for the multiracial composition of many troops.

“My mother and father had just moved us to Anaheim,” Loretta Sanchez says. “My mother said, ‘Let’s put you in Brownies, so you can make some friends.’ I loved wearing the Brownie beanie, and after school we would go to Hazel Peterson’s home. . . . I was Mexican American, and there were no other Mexican Americans at that school. It had been very difficult.”

Sanchez is Congresswoman Sanchez (D), representing California’s 47th district. She belonged to Troop 1440, and she is one of the dozens of accomplished women of today who saw Girl Scouts as a flagstone on the path to success. Hillary Rodham Clinton was a Girl Scout, as were Laura Bush, Madeleine Albright, Janet Reno, Sandra Day O’Connor, Joyce Brothers, Katie Couric, Lucille Ball, Grace Kelly, Dakota Fanning and Queen Elizabeth II. (In England, they’re called Girl Guides.)

“I was the best cookie-seller,” Sanchez remembers. She would stand outside the bank on Friday afternoons, waiting for people to exchange their paychecks for Thin Mints.

The development of budding businesswomen has been a backdoor bonus of the organization since the first homemade sugar cookie became a piece of oral history in 1917. Pound the pavement. Sell the Samoas. Use the money to achieve your dreams.

* * *

Girl Scout: Is this made from

real lemons?

Wednesday Addams: Yes.

Girl Scout: Well, I’ll tell you what. I’ll buy a cup if you buy a box of my

delicious Girl Scout cookies.

Do we have a deal?

Wednesday Addams: Are they made from real Girl Scouts?

— “The Addams Family” movie, 1991.

* * *

The founder of this, all of this, was Juliette Gordon Low, who died more than 80 years ago but who is still referred to by Girl Scouts as if she were a dear friend, by her childhood nickname of Daisy (also the name for the very youngest Scouts).

Daisy was born in Savannah, Ga., the daughter of a native Southerner and his Yankee transplant wife. “She was the belle of the ball,” says Stacy Cordery, who wrote a Low biography geared toward adults. “She was outgoing, funny, witty, quirky, interested in theater and athletics.” She caught the eye of William Low, whose wealthy father was in the cotton business, but their wedding foreshadowed trouble ahead — a grain of rice tossed at the happy couple lodged in Daisy’s ear, puncturing her eardrum and resulting in lifelong partial deafness.

They moved to London, where William began palling around with the Prince of Wales, canoodling with a mistress and being a general toad. But Daisy was a devout Episcopalian. She was raised with a sense of duty that prevented her from agreeing to a divorce when William asked for one. She eventually changed her mind, but before the separation could be finalized, her husband died of a stroke.

“You have to understand,” Cordery says. “She had a broken heart to nurse. She was stunned and shocked by his betrayals. She was very sad about being childless. The socially sanctioned purpose of women at the time was to be a wife and mother,” and she’d failed at both.

After her husband’s death, Daisy was drawn to the idea of charitable work, something that she’d always wanted to pursue but that William had looked down on. In London, she’d met Robert Baden-Powell and had become intrigued by his fledgling “scouting” movement — designed to physically and mentally strengthen children through outdoor activity. It was targeted to boys, but girls were showing up in handmade uniforms, begging to be included.

William Low had given his wife a strand of pearls on the occasion of their marriage.

Daisy sold the pearls to pay for the Girl Scouts.

The first meeting of the first troop was in Savannah on March 12, 1912.

“Their uniforms were considered too masculine,” says Susan Miller, a Rutgers University professor who has studied youth organizations. “The Boy Scouts sued them for copyright and trademark violation.”

Daisy pressed on.

“Daisy Low’s life, until that point, was in some ways a failure,” Cordery says. “But what she learned is that training girls to be prepared was necessary. Because you just didn’t know when your life was not going to go according to plan.” The punctured eardrum, the bad marriage, the realization that sometimes you have to be your own handsome prince — all of it suddenly came together.

“Only Daisy Low,” Cordery says, “could have created the Girl Scouts.”

* * *

Well-educated women can take up translating, as stockbrokers, house decorators, or agents, managers of laundries, accountants, architects. . . . The numbers of women who have taken up aviation prove that women’s nerves are good enough for flying.

— “How Girls Can Help Their

Country,” 1913.

* * *

But enough with the history professors, the biographers, the members of Congress.

The Girl Scouts have always been about the girls, and the best way to discern what the organization means is to hunker down with a bunch of 11-year-olds.

On a Wednesday evening, the girls of Troop 1273 gather at a Silver Spring community center for their weekly meeting. Today they’re preparing a presentation on Liberia for an international celebration. Half of the troop is working on an info poster; the other half is mixing a batch of sweet rice bread.

On the cooking side, Chaya Blonder rattles off the troop’s recent activities while Alisa Scott and Sarah Kessler measure out ingredients.

“We went to Madame Tussauds — ”

“How many bananas have we put in?”

“ — And we went along the Underground Railroad — ”

“Did anyone add the oil?”

“ — And we slept in this museum — ”

“The way you mix the bread is like da Vinci. I’m more like one of those splatter painters.”

These girls are using some of their cookie proceeds to take a day trip to Hersheypark in Pennsylvania and giving the rest to a nonprofit group called Women and Water.

Did you know, Chaya and her friend Sydney Acuff explain to a visitor, how many people die from unsafe water?

The glue on the poster is drying, and the rice bread is baking in the oven. The girls wipe down their tables and talk about politics. Liberia’s leader, Ellen Johnson Sirleaf, is a woman, they explain. She won the Nobel Peace Prize. That’s one of the things they like about the country.

What about the United States? When do the girls think that the United States will have a woman in its top elected position?

“Probably,” Sydney says thoughtfully, organizing some markers, “when I am old enough to be president.”