Margaret E Knight: The Most Famous Woman Inventor of the 19th Century | History Hit

Margaret E Knight: The Most Famous Woman Inventor of the 19th Century

Amy Irvine

20 Oct 2022
Patent model for the Paper Bag Machine
Image Credit: Smithsonian

Margaret E Knight was a prolific female American inventor of the 19th century who created many machines and mechanisms used for a variety of industrial and everyday purposes. She is most noted for her invention of a machine used to make flat-bottom paper bags, facilitating the mass production of these. Indeed this type of paper bag is often used by many Americans in particular to carry groceries and packed-lunches to this day. Knight obtained this patent at a time when few women held any intellectual property, making her achievement all the more impressive, becoming a symbol for women’s empowerment. 

By the time she died in 1914, Knight had gone on to patent 27 inventions and had made around 90 inventions, with her obituary describing her as a ‘woman Edison’. Here we look at her life, inventions and legacy.

Early life and first invention

Margaret Knight was born in York, Maine in 1838 and is said to have enjoyed working with her hands from a young age. She had a knack for woodworking tools and invention, and made toys for her brothers as well as kites and sleds.

After the death of her father, the family moved to Manchester in New Hampshire. Her formal education was limited to secondary school – after this, aged 12, she took on a job working long hours in a cotton mill along with her siblings to help their mother make ends meet.

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Mills were notoriously dangerous, and while there, Knight witnessed a serious accident where a worker was stabbed by a steel-tipped shuttle that shot out of a mechanical loom. Within weeks, and still just 12 years old, she had invented a shuttle restraint system – a safety device for controlling shuttles in powered textile looms. Unaware of the patent system, this device was never patented, but was later adopted by other mills across the area and soon the rest of the country, becoming a standard fixture on looms.

Knight developed health problems and was unable to continue work at the cotton mill. She went on to hold several jobs in her teens and early twenties, including in home repair, photography, engraving and furniture upholstery.

The flat-bottom paper bag machine

In 1867, Knight started work at the Columbia Paper Bag Company in Springfield, Massachusetts. She soon noticed that the envelope-shaped machine-made paper bags being produced could not stand on their bases, being too weak and narrow, and poorly suited to holding bulky items. The existing machines were already the subject of three patents, and at the time, sturdier flat-bottomed paper bags were made by hand and thus expensive.

Rather than folding each paper bag by hand, Knight realised the process could be improved if automated. Flat-bottomed bags were already in general use in Britain, and a semi-mechanised apparatus was used in the making of them (patented by James Baldwin in 1853). However, Knight thought the process could be fully automated, and began experimenting with an attachment to the machine that would cut, fold and glue paper to form flat, square-bottomed bags. Unlike their flat predecessors, these new bags were much stronger, and their ability to stand made them far more practical.

By 1868, her machine was fully operational, and had already vastly improved the uniformity of her company’s bags and output. Having learned her lesson, Knight knew she had to apply for a patent for her machine. 

Margaret E. Knight IN 1912

Image Credit: Boston Sunday Post, Public domain, via Wikimedia Commons

However, Charles Annan, a machinist who visited the shop where Knight’s prototype was being built, stole her design and patented it first. When Knight attempted to patent her own work, she discovered Annan’s patent and took him to court in 1870. Annan argued that Knight ‘could not possibly understand the mechanical complexities of the machine’ and that she hadn’t succeeded in creating a working machine whereas his machine was different.

Knight responded by providing copious evidence including meticulous hand-drawn original blueprints of the machine’s design, journals, models and many witnesses, who testified she had been making drawings and models since 1867. Swiftly debunking Annan’s unsubstantiated claim, she won the case, receiving her patent in 1871. Knight then co-founded her own paper bag company – the Eastern Paper Bag Company. Her machine enabled the mass manufacture of flat-bottomed bags, transforming the speed of their production. Such was its significance that Knight was even decorated by Queen Victoria in 1871 for her invention.

Having no interest in managing the business, Knight chose to receive royalties from the Eastern Paper Bag Company instead, and continued her work as an inventor.

Other inventions

Knight continued inventing things throughout her life, yet failed to profit much from her work. In the mid-1880s she created patents for a dress and skirt shield (1883), a clasp for robes (1884) and a spit (1885), and later obtained 6 patents for sole-cutting machines used in the manufacturing of shoes. 

She also invented a numbering machine (1894), a window frame and sash (1894) and several devices relating to compound rotary engines (between 1902-1915).

Compound rotary engine, 1902

Image Credit: Margareth E. Knight, Public domain, via Wikimedia Commons


I’m only sorry I couldn’t have had as good a chance as a boy
Margaret E Knight

Whilst Margaret E Knight was not the first woman to receive a patent, she was one of the most productive female inventors. By the time she died in 1914, Knight had patented 27 inventions and had made around 90 inventions, leading her obituary to describe her as a ‘woman Edison’. Knight was inducted into America’s National Inventors Hall of Fame in 2006.

Her largely self-taught abilities, patents, inventions and great interest in machinery are extremely impressive in their own right, yet significantly Knight achieved these at a time when few women held intellectual property. (In America today, fewer than 10% of ‘primary inventor’ patent awardees are female, highlighting Knight’s impressive achievements back in the 19th century.) 

Many of her inventions are still used today or have been improved upon into something more advanced, and the barriers Knight overcame and her legacy to the world of science and technology continue to inspire today.

Amy Irvine