09/12/2025
Margaret E. Knight was an awesome inventor and a woman whose inventions saved lives, changed the face of brown bags and so many more.
She had to fight through the courts to prove one of her inventions was truly hers after a guy pinched her idea and got it patented.
Thankfully she led the way for more great women to engineer great innovations
February 1871. Washington, D.C. Margaret Knight walked into the Patent Office Building carrying notebooks, diaries, photographs, patterns, models, and years of meticulous documentation. She was 32 years old, and she was about to make history.
A man had stolen her invention—a machine that could automatically cut, fold, and glue flat-bottom paper bags. He'd patented it under his own name. Now he stood before a judge claiming that no woman could possibly have designed something so sophisticated.
Margaret Knight was about to prove him catastrophically wrong.
Knight was born February 14, 1838, in York, Maine, to Hannah Teal and James Knight. Even as a small child, "Mattie" preferred woodworking tools to dolls, famously declaring that "the only things I wanted were a jack knife, a gimlet, and pieces of wood." She built kites and sleds for her brothers, earning a reputation around town for her impressive craftsmanship.
Her childhood ended abruptly when her father died and the impoverished family moved to Manchester, New Hampshire, seeking work in the cotton mills. At just 12 years old, Knight began working long hours in brutal conditions to help her widowed mother make ends meet.
The textile mills were death traps—dangerous machinery, no safety standards, exhausted workers, and frequent accidents. One day, Knight witnessed a steel-tipped shuttle shoot out of a mechanical loom and stab a young boy. Such accidents happened regularly, maiming and killing workers.
Within weeks, the 12-year-old Knight had invented a shuttle restraint system—a safety device that would automatically stop the machine if something went wrong. Her invention swept through cotton mills across the country, becoming a standard fixture on looms and saving countless lives.
But Knight knew nothing about patents. She received no compensation, no recognition, no credit. She wouldn't make that mistake again.
Through her teens and twenties, Knight worked a series of technical jobs—home repair, photography, engraving, upholstery. She taught herself multiple trades, becoming comfortable with tools and machinery that most women never touched. Every job added to her arsenal of practical knowledge.
In 1867, at age 29, Knight moved to Springfield, Massachusetts, and began working at the Columbia Paper Bag Company. The job paid little, but it gave her something more valuable: a problem to solve.
The company produced envelope-shaped paper bags using machines—thin, weak bags that couldn't stand upright and were poorly suited for groceries, hardware, or any bulky items. Stronger flat-bottom bags existed, but they had to be folded by hand, one at a time, making them expensive and slow to produce.
Knight looked at the inefficient manual process and thought: there has to be a better way.
Within a month, she'd sketched a machine that could automate the entire process. Within six months, she'd built a working wooden model that would cut, fold, and glue flat-bottom bags with the turn of a crank. The "rickety" prototype, as one witness later described it, pumped out over 1,000 bags.
But Knight knew the wooden model wasn't enough for a patent. She needed an iron prototype—something sturdy, precise, professional. She hired a local machinist to build it from her specifications, then moved to Boston to refine the design with two more machinists.
At the second machine shop, a man named Charles Annan stopped by. He seemed curious about the invention, asked detailed questions, requested a demonstration. Knight, trusting and focused on her work, allowed it.
Months later, when Knight finally completed her machine and filed for a patent, she received shocking news: her application was rejected. A patent had already been granted to Charles Annan for a nearly identical machine.
Annan had stolen her design, copied it, lied on his patent application, and tried to claim credit for years of her work.
Knight hired a lawyer and marched into Washington, D.C., determined to fight. The patent interference lawsuit began in fall 1870. For 16 days, testimony filled the courtroom. Knight spent $100 per day on legal costs—equivalent to about $2,500 today—a staggering sum she'd saved from years of work.
Annan's defense was as predictable as it was insulting: she could not possibly understand the mechanical complexities of the machine. The implication was clear: women didn't have the intelligence, the technical knowledge, or the capability to design sophisticated machinery. Therefore, his patent must be legitimate, and hers must be fraud.
Knight responded with evidence. Mountains of evidence.
She presented meticulously detailed hand-drawn blueprints showing every component of the machine—gears, springs, folding mechanisms, gluing apparatus. She showed journals documenting her development process from 1867 forward. She displayed multiple models demonstrating the evolution of her design.
Then came the witnesses. Machinists from all three shops testified that Knight had provided detailed specifications, supervised construction, made technical adjustments, and demonstrated deep understanding of every mechanical principle involved. They confirmed she'd been working on drawings and models since 1867—long before Annan had ever seen the machine.
Annan had nothing. No drawings. No documentation. No witnesses. No credible explanation for how he'd supposedly invented something remarkably similar to what Knight had been publicly developing for years.
The judge's verdict was decisive. Knight won. Completely, thoroughly, undeniably.
On July 11, 1871, Margaret Knight received U.S. Patent No. 116,842 for her paper bag machine. She became the first woman in American history to win a patent interference lawsuit.
With her patent secured, Knight co-founded the Eastern Paper Bag Company in Hartford, Connecticut, with a business partner. She negotiated an upfront payment of $2,500 plus royalties capped at $25,000—comfortable income, though far less than the invention ultimately generated for the company.
Knight had no interest in managing a business. She wanted to invent. So she sold the rights, collected royalties, and returned to what she loved: solving problems that no one else had solved.
Her paper bag machine transformed retail commerce overnight. The strong, flat-bottom bags could carry groceries, hardware, books—anything that needed transporting. Workers carried lunch in "brown bag" lunches. Students packed sandwiches. Stores distributed purchases. The bags were everywhere, utilitarian and ubiquitous.
Knight continued inventing for the rest of her life. She received a second patent in 1879 for improvements to her original paper bag machine. She designed a dress and skirt shield in 1883, a clasp for robes in 1884, a cooking spit in 1885. She invented window frames, shoe-cutting machines, and a compound rotary engine.
By the time she died in 1914 at age 76, Knight held at least 26 patents and claimed 89 total inventions across multiple fields. Her obituary called her a "woman Edison," though in truth, she was something more—she was Margaret Knight, and that name deserved to stand on its own.
Knight never concealed her gender when promoting her work. While many female inventors used only initials to hide their s*x, Knight boldly identified herself as "Margaret E. Knight" on every patent. She became a hero to women's rights activists, proof that women could achieve in mechanics and engineering when given the opportunity.
She lived modestly but independently—unusual for a single woman in her era. She never married, instead devoting her life to invention, teaching photography and art to children at Cambridge Settlement House, and continuing to push boundaries in fields dominated by men.
In 1871, Queen Victoria decorated Knight for her invention. The Smith College Medal honored her work. But perhaps her greatest achievement wasn't any single invention—it was changing how society viewed what women could accomplish.
Today, a scaled-down but fully functional patent model of Knight's 1879 improved paper bag machine sits in the Smithsonian's National Museum of American History. An impressive assembly of gold-colored metal gears, springs, and parts mounted on deep brown hardwood, it offers silent testimony to Knight's genius.
More importantly, machines based on Knight's design still produce flat-bottom paper bags worldwide. Every brown bag lunch, every grocery sack, every gift shop purchase carries her invisible legacy. Thousands of machines in factories across the globe operate on principles she invented over 150 years ago.
The story of Margaret Knight matters not just because she invented something useful, or even because she fought and won against theft and s*xism. It matters because she refused to accept limitations others tried to impose on her.
At 12, she solved a problem that was killing workers. At 32, she beat a fraud in court with nothing but evidence and determination. Throughout her life, she proved that skill has no gender, that genius appears in unexpected places, and that the only real barrier to achievement is the refusal to try.
When Charles Annan claimed no woman could understand complex machinery, he made a fatal miscalculation. Margaret Knight didn't just understand machinery. She designed it, built it, patented it, defended it in court, and watched it transform an entire industry.
The flat-bottom paper bags in your pantry, the ones you've used thousands of times without thinking—they exist because a woman refused to be told what she couldn't do.
Remember her name. Margaret E. Knight. The inventor who proved them all wrong.
