Margaret E. Knight

A man tried to steal her invention by arguing in court that women aren’t smart enough to build complex machines.

Margaret Knight was raised by her widowed mother after her father died.

By age 12, she’d left school and started working in a cotton mill in Manchester, New Hampshire to help support her family.

One day, she saw a steel-tipped shuttle shoot out of a loom and stab a worker in the chest.

Injuries like this happened all the time.

So within weeks, Knight invented a shuttle restraint system.

It either stopped the loom when the shuttle thread broke, or blocked the shuttle physically from flying out.

We don’t know exactly, she didn’t patent it.

But that was just the beginning.

In her early 30s, Margaret was working at Columbia Paper Bag Company in Springfield, Massachusetts.

She noticed that the bags being made (basically envelope-shaped) were flimsy, couldn’t stand up, and weren’t useful for groceries or tools.

Flat-bottom bags were better but they had to be folded by hand.

Expensive. Slow. Inefficient.

So 1868, Margaret built a wooden prototype of a machine that could cut, fold, glue, and create the flat-bottomed paper bag we still use today.

One machine doing the work of 30 people.

For the first time ever, these bags could be mass-produced.

But to patent it, she needed a working metal model.

So she hired a machinist.

That’s when the theft happened.

Charles Annan, a man who worked at the shop where the iron prototype was being built, saw the blueprints.

He filed a patent for her machine. Under his own name.

When Knight went to file hers, she found out his application had already been submitted.

She sued him for patent interference in 1870.

Annan argued she couldn’t possibly understand the mechanics.

He said “a woman” wasn’t capable of designing such a complex machine.

Knight brought the receipts. Blueprints. Detailed journals. Eyewitnesses. Her original models. Her notes from 1867.

The trial lasted 16 days.

She paid $100 a day in legal fees.

But she won.

And in 1871, the patent was granted to her.

She became the first woman in the U.S. to win a patent interference case.

And she commercialized her idea.

With a business partner, she launched the Eastern Paper Bag Company in Hartford, Connecticut.

She took royalties instead of running operations.

They capped out at $25,000 but that income allowed her to keep inventing full time.

Altogether, she held at least 27 patents, including:
- A skirt and dress shield
- A clasp for robes
- A cooking spit
- Six machines for cutting shoe soles
- A window frame and sash
- Parts for rotary engines and internal combustion motors

And she created dozens more inventions that she never patented.

When The New York Times profiled her in 1913, she was “working 20 hours a day on her 89th invention.”

She was called the “Lady Edison.”

Decorated by Queen Victoria.

And inducted into the National Inventors Hall of Fame in 2006.