top of page
  • Writer's pictureMatilda Butler

Ever Thought About the Grocery Bag You Use? Who Invented It?

Updated: Jun 3, 2022


Inveterate Inventor

Join Us Today as We Reveal the Life of the Amazing Woman -- Margaret E. Knight




  1. Take Yourself Seriously.

  2. Trust Your Ideas.

  3. Pursue Your Goals to the Conclusion.

“Paper or plastic?” asked the grocery clerk?

If you say "paper," then you get a brown kraft bag that is unfolded by the bagger and stands on a flat bottom. Notice how many groceries it holds -- perhaps canned refried beans, fresh carrots and green beans, a sack of oranges, a dozen eggs, a pint of strawberry ice cream, a loaf of bread, and perhaps more.

But that wasn’t always the case. Can you even imagine the paper bags that came before our current, well-known flat bottomed ones?

They are described as an oversized envelope — minus the top closure flap. As you can imagine, these paper (envelope-type) bags didn’t hold much. Just how much could you put in a large envelope! (Unsure? Just ask our cat below. She loves a flat bottomed paper bag. It holds so much more than an envelope-type bag.]

How Did We Get From Large Envelopes to Flat-Bottomed Bags?

You can thank Margaret Knight. Margaret (she was called Maggie by family and friends) always tried to figure out how to make machines better. Even at the age of 12, she was already on her way to being a professional inventor.

Remember, she was 12 in 1850 and was working at the Amoskeag Manufacturing Company in Manchester, New Hampshire. After the death of her father, Maggie, her mother and two brothers all worked at the cotton weaving mill in order to have enough money to live.

The loom was designed so that the shuttle Maggie threw would fall into a cup at the end and be automatically thrown back — at a high velocity. As long as Maggie and other workers were extremely mindful, they would then pick up the resting shuttle and send it back to the cup. Then the whole process repeated.

The problem was with the shuttle that the cup sent flying back. If a worker wasn’t careful, it would hit her arm or hand and cause enough damage to lead to missed work (and missed income, of course) while the wound recovered.

This wasn’t good for workers, obviously. But it turns out that injured workers also weren’t good for mill owners as it meant that a certain percentage of workers were out every day. That resulted in idle equipment and fewer bolts of finished fabric per day. And that meant lower profits.

In Walks Maggie

One day at work, Maggie saw blood pouring down the arm of the child at the loom next to her. As she looked at the machine, she got an idea. She took out a small piece of paper and short pencil that she carried in her pocket and made a couple of quick drawings. She couldn’t do much since she had to be working on her loom. But later that night and over the next week, she drew and redrew the modification that would make the machine safe for workers.

Would the Mill Manager Listen to Her?

Fortunately, the manager wanted the workers at their looms. So when Maggie demonstrated how her design could reduce the risk of injury, he paid attention. Soon, all the machines had been modified and that solved the problem.

But What Does a Loom Have to Do With a Flat-Bottomed Bag?

Good question. I told the story of Maggie at the mill to illustrate how inventing was the way her mind worked. And she had enough determination and inner strength to not just have ideas, but to create detailed plans, and then to present her inventions to a manager. She carried through. I imagine that she saw no point in just having a good idea. She was ready to do the work to ensure the idea was put into practice.

…Now, as to the Flat-Bottomed Bag

A few years later, Maggie was working for Columbia Paper Bag Folding Company. A machine produced the envelope-type bags. Maggie’s job was to count, stack, and tie bundles of bags that the machine produced. With her active mind, this was an incredibly boring task. She, after all, was a problem-solver. So it’s not surprising that she soon envisioned a flat-bottomed bag and, of course, she started considering what kind of machine could produce it. She already was working at a machine and she could see how it made folds and glued them into place.

At night, after her long shift, she began working on a design to modify the current piece of equipment. It took her quite a while as she also decided to build a prototype. It was clunky. She was an inventor, not a craftsperson. But the machine worked. Once it was ready, she lugged her prototype to work and put it on her work table. She took a piece of paper and fed it through the machine. It produced a flat-bottomed bag.

The supervisor came over to ask why she wasn’t doing her job. She replied, “I’m making flat-bottomed bags. Here’s one I just made.” She showed how the bag looked when open—standing on its bottom. The supervisor said, “Can you make another one?” “Sure,” she said. And then she took another piece of paper, put it through the machine, and produced a second bag. The supervisor had another manager come look and asked how many of these bags she could make. “As many as you like,” she responded. She put in another piece of paper and another flat-bottomed bag came out.

It took a number of conversations and demonstrations, but the company was certain that this new product would be profitable for them. No competitor had anything like this flat-bottomed bag. She wanted to patent the new machine, but first needed a better prototype. She was given time off to go to Boston to a fabricator who could produce it to the specifications in her extensive drawings.

That’s When Trouble Tried to Infringe on Her Way to a Patent

Maggie explained her invention to the fabricator and even demonstrated how the prototype worked. One customer, in particular, seemed fascinated. His interest somewhat flattered Maggie because it showed that there was value in a flat-bottomed bag.

Two Weeks Later...

When she returned two weeks later to pick up the new prototype, “it just happened” that the same customer was there again. Maggie asked for the machine and the customer said, “I’ll go get it for you. I know where it is in the back.” The fabricator even joked, “Charlie, it sure is nice to have an employee-customer that I didn’t have to pay.” Later Maggie would recall that name--Charlie.

She took the prototype home and saw that some improvements were needed. She spent several more months, always working on her own time, to create a better machine. She knew a lot about patents by then and had all of her notes with dates. Each drawing page was dated and signed.

By the way, she used Margaret E. Knight as her signature. Other women of the period used their husband’s name or used an initial for the first name. They did that to get around the prejudice against women as inventors.
The prevailing prejudice was that women weren’t smart enough to figure out new pieces of equipment or any other new invention. That was the domain of men.

Even Maggie’s boss first assumed that her husband had invented the flat-bottomed bag. When she said she wasn’t married and that she had invented the machine, the boss next assumed her brother had invented the machine. She would not be put down or denied her intelligence to create the machine. Finally, the boss understood that it was Maggie’s original work.

And fortunately for Maggie, she had not been hired full-time. So as a part-time employee, the design belonged to her and not to the company.

The Patent Application

Maggie knew a lot about patent applications. She had everything in order, filed the paperwork, and paid the fee to the US Patent Office. It was about three months later that she received a letter. To her GREAT surprise, her application was denied because a patent had already been granted for a machine that created flat-bottomed bags. The letter said that if she wanted to protest, she would be granted a hearing.

And Who Had the Patent?

Remember the customer in the fabricator shop? Yup. You’ve got it. He stole Maggie’s design, drew it, and submitted it to the US Patent Office. Upon seeing his name as the holder of the patent, Maggie remembered that nickname -- Charlie.

Protest She Did

And you bet Maggie did protest. She hired the best patent lawyer she could find even though it cost her $100 a day. She had savings but spent most of her money by the time the 16-day trial ended.

She had lots of evidence that the design was her unique effort. Because she kept notes, she could say when she first got the idea and why she created the machine. She had all of her early drawings (each dated and signed, of course) right up to the much better design that she submitted for the patent.

After 16 long days of testimony, Maggie had convinced the Commissioner of Patents that her design was original with her and that the other person had stolen it from her.

And Margaret E. Knight became the first woman in American history to win a patent interference lawsuit.

And the customer? His name was Charles Annan and when queried about his design, he wasn’t sure when he first got the idea or even why it occurred to him. He had no notes of an earlier design he had worked on before the one he submitted. It became obvious he had stolen Maggie's design.

Next Step?

Maggie had used most of her money by now and knew she needed an investor—a partner to open her own paper bag company. She advertised in the newspaper but only heard from one person. She worked on her presentation and set up a meeting. She made her pitch and the person said he would like to develop a company with her. He offered her $2500 for the invention and $25,000 in royalties—to be paid as earned from sales. She thought about it. She had hoped for more money for the invention, but realized that one-in-the-hand is better than two-in-the-bush. She accepted the offer and the two of them opened the Eastern Paper Bag Co. It was a successful company. However, Maggie often had difficulties with the male employees who refused to believe that she knew more about the machine than they did. The company profitable.

By the way, Margaret E. Knight was awarded Patent # 116842 for the flat-bottomed paper bag machine.

That was just one of the 89 inventions including 27 (or 26, depending on the source) patents she obtained over her 75 year life. She died on October 12, 1914 in Framingham, Massachusetts. At the time, she was working on her next invention.

Margaret E. Knight Patents

CREDIT: Boston Sunday Post, 1912


When Margaret was inventing, men were granted 98% of all patents so obviously women only held 2% of patents. And now? Currently women hold 19% of patents. I think it is fair to say “only 19%”. We need more women who consider themselves innovators.

If you like to innovate. If you have the ideas and the persistence to develop your unique ideas, then we urge you to pursue your concepts and carry them through with detailed plans and obtain your patent(s). We're all waiting!




Below is a link to a fantastic 46 minute audio reenactment of Margaret Knight pursing her patent for the flat-bottomed paper bag -- created by the Smithsonian. Her story comes to life!

Margaret Knight’s Story is an Inspirational One

She didn’t back down even at the young age of 12. She stood up for herself. She used her talents and was unafraid (or at least not willing to let fear stop her). In considering her life, we found a 3-part inspirational message.

We hope Maggie’s life will inspire you as it has inspired us.



  • Take Yourself Seriously.

  • Trust Your Ideas.

  • Pursue Your Goals to the Conclusion.

What is the inspirational message you found?


By now, you have probably noticed a pattern. At the end of most of our blogs, we include a prompt for writing and/or for action. Why? I don't know about you, but I've often scanned an article, felt inspiration or encouragement, and then promptly forgot about it. We know you are busy, so our prompts are designed to just give you enough time to focus on writing or taking action to help you incorporate the week's inspiration into your life.

Today, we hope you'll take 5 minutes to find a way to apply the lesson from Margaret Knight to your own life. Don't think of yourself as an inventor? The inspiration from her life can be applied to many parts of your own life -- personal, professional, leisure, etc.

  • Take Yourself Seriously.

  • Trust Your Ideas.

  • Pursue Your Goals to the Conclusion.

  • Choose just ONE of the three inspirations above. Then write for 5 minutes on how you can take action today by letting the words inspire you.

    1. How might you "take yourself more seriously?" Do you undervalue yourself? Don't let self-doubt curtail your life experiences.

    2. How could you implement the notion of "trusting your ideas?" Do you think that others always have the great ideas and that your ideas are "dumb" or not "feasible." Not every idea is great but don't let that hold your back. Write about one idea that you would like to pursue.

    3. I bet your have goals right now that get pushed to the back while you just cope with life. Well, write about how you will "pursue your goals (well, just one of them) to the conclusion. What does it take for you to make progress with a goal that is important to you? Write about this and see what you can do this week to get yourself back on the path toward your goal.

Then remember to be inspired by your own life as you move forward.

Missed Our Previous Blogs? Check these out!

Rosie the Riveter's Riveting Story -- Find out the connection to Jackie Kennedy's fashion designer and Rosalind Palmer Walter (major funder of public television).

Wendy the Welder (Rosie's Co-Worker)

Want More Stories about Amazing Women? More Inspiration for Your Own Life?

Be sure to scroll down below this post and sign up to receive notifications of our new blogs ...

...AND get a 40% discount on any item in our Etsy store.


Rated 0 out of 5 stars.
No ratings yet

Add a rating
bottom of page