Margaret E. Knight – Inventor Extraordinaire

By Jaime Seltzer

Margaret was born in a small town in Maine in 1838. Her father died when Margaret was very small, and so she lived with her widowed mother and two older brothers.

Though they were poor, Margaret was rich in imagination and native technical skill. Using her father’s old tools, she invented toys for her older brothers – mechanical things that moved when you blew on them or pulled a string – and a foot warmer for her seamstress mother, who often sat up late into the evening sewing. She designed and fabricated different kites for her brothers to play with, and fashioned sleds for them to use. Neighborhood children would pay her a quarter or a dime to make them special things, and so it became clear to Mattie from an early age that her cleverness with materials and design could fetch her both respect and a little extra money for her family.

When Mattie was eleven, her older brothers were set to work in a local textile mill, and she was sent to school. Safety standards were not exactly the rule of the day in the 1850s, and Mattie was witness to a terrible accident. Immediately she went home to her idea book and designed a stop-motion textile processer – a machine that would stop immediately if something were caught in it. The device was adopted by the mill immediately. At this time, she was twelve years old, but she had already invented dozens of different things for the use of her family; the textile mill was a project for the greater good, just another design for Margaret to add to her notebook. She was too little and too uneducated in the ways of the world to realize that she should really get a patent so that she could profit off of her life-saving invention.

Over the course of her lifetime, Margaret held the patents for her square-bottomed bag creator, machines that cut the soles of shoes, a machine that numbered items automatically, a design for a lovely window sash, and at least three different kinds of engines, two rotary and one internal combustion.

Mattie herself ended up in factory work, which often brought in more money those days than any other job for which an uneducated person might be hired. It was in the 1860s while working at a factory that produced paper bags that she realized how much easier the whole business would be if paper bags had square bottoms. If you are thinking well, yes, of course it would be; all paper bags have square bottoms because that is the only way they will stand upright as you load them, you are thinking all of that because Margaret E. Knight invented the flat-bottomed bag and the machine that would make it, and no one has seen much use for anything else, ever since.

Mattie spent a few years tinkering at home until she had produced a model of the machine, but made of wood and brass. She took it to an iron-worker to have them cast the pieces; and, while there, a man named Charles Annan saw the complicated and beautiful device, and spied on her in order to determine what it was for and how it was made. By the time that Mattie was ready to apply to the U.S. Patent Office (she’d become a bit wiser since she was twelve), she found that the seedy guy who’d been hanging around her workshop had already applied for one.
Luckily for Mattie, she’d been working on the design for ages and been fabricating the parts one at a time for years, and she had all the drawings, cuttings, and failed bits and bobs to prove it. She took Charles Annan to court to support her claim.

Annan’s contention was that a woman couldn’t have been clever enough to come up with such a complicated device, since women’s brains could not comprehend machinery, and therefore the patent was rightfully his. The court laughed very loudly and awarded the patent to Knight.

Margaret E. Knight

Margaret E. Knight and her card in Women in Science.

It’s probably accurate to say that Margaret invented hundreds of different items, but the number of patents in her name are smaller – she invented so much that she only bothered to get a patent for some of it. Part of this was indubitably because manufacturing was expensive and time-consuming, and Knight was a factory girl who could not really stop working long enough to simply sit down and write up patents all day long. When she did begin to have more of a hand in the manufacture of her own items, co-creating a paper manufacturing company, men who worked for her were dubious of her skill until it had been demonstrated to them firsthand, refusing to follow her instructions. As the inventor of the machine they were using, that must have been very wearying!

Over the course of her lifetime, Margaret held the patents for her square-bottomed bag creator, machines that cut the soles of shoes, a machine that numbered items automatically, a design for a lovely window sash, and at least three different kinds of engines, two rotary and one internal combustion. Her designs, all drawn by hand, are incredibly intricate and impressive, even the ones created when she was still a little girl; and her handmade machines are both impressive and beautiful, created with an engineer’s mind and a designer’s eye.

At the time of her death in 1914, the paper hailed her as a ‘female Edison’. What separated Edison and Knight was Edison’s propensity to develop inventions that were not always his own designs (he particularly enjoyed nicking Tesla’s ideas). It was in Knight’s nature to invent something useful and beautiful but not necessarily patent it if she thought it could be used for the public good, like her stop-motion machine. Though she invented at least a hundred items, she held about twenty patents.

Her original bag-making machine still gleams on display at the Smithsonian Museum.

Margaret Knight – Invention of the Paper Bag Machine. (2008). In: Famous Women Inventors. Retrieved from
Margaret E. Knight (1838-1914) (n.d.). In: National Women’s History Museum. Retrieved October 3, 2015 from
Mohammed, H. (2014, January 16). Meet Margaret E Knight – The Paper Bag Pioneer Who Had Her Inventions Stolen by a Man. In Women Rock Science. Retrieved October 3, 2015 from

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