Margaret Eloise Knight (1838-1914) was a prolific late 19th- and early 20th-century inventor. She made improvements to various devices but is best known as the creator of the flat-bottom bag used in the retail industry.
Margaret Eloise Knight was born on Feb. 14, 1838, in York, Maine, to Hannah (Teal) and James Knight as the youngest of five children. As a child, she was inclined to make sleds, kites and wooden toys — rather than play with dolls. Her widowed mother then moved the family to Manchester, N.H. Margaret started working in 1850 at the Amoskeag Manufacturing Company, a textile company. One day she saw a steel-tipped flying shuttle used to weave thread break off and injure a young worker. Although she was only 12 years old, Margaret created a metal device to keep the shuttle secure. Unaware of the process for obtaining a patent, she failed to profit from what became a widely adopted innovation.
Margaret Knight Gets a Patent
Margaret left textile employment as a teenager and then found work in the upholstery, photography and engraving industries before taking a job in 1867 with the Columbia Paper Bag Company in Springfield, Mass. Observing the need for improvements in workflow, she obtained her first patent (US109,224) on Nov. 15, 1870. She described her invention as an “Improvement in paper-feeding machines” that found use in printing presses and machines for folding paper.
Her most notable invention — making flat-bottomed paper bags — came a year later.
Initially, a paper bag was hand-made by merchants for carrying food and other small items. As early as 1852 Francis Wolle of Pennsylvania obtained the first patent for a “machine for making bags of paper.” It could feed, cut, and fold paper into 1,800 bags an hour with a flat bottom, shaped like an envelope. However, this machine (and patents for improvement in 1855 and 1858) yielded bags that could not stand upright, were not strong and had limited capacity to hold items.

Soon after obtaining her first patent, Knight began working on a wooden prototype machine that could improve upon the bags made by Wolle. Her invention hinged on taking a paper tube and folding the end of it three times into a flat square bottom. By applying paste as the folding process occurred, the bottom quickly fastened and the brown bag with the wide base was removed from the machine. The prototype machine proved successful, so Knight filed for a patent using an iron model. However, Charles Annan saw the iron version being built, stole the design and filed a patent request.
Legal Victory for Margaret Knight
Knight lodged a successful patent interference suit against him and obtained a patent for an “Improvement in paper-bag machines” (US116,842) on July 11, 1871. Annan had made an ambiguous argument about having a different machine, but Knight successfully defended her expensive lawsuit through a copious trove of hand-drawn blueprints, journals and models. She also produced numerous witnesses attesting to her skills. Attempting to benefit from her patent, Knight co-founded the Eastern Paper Company in Hartford with a Massachusetts businessman. Not wanting to stay and help manage the company, she settled for an initial payment of $2,500, company stock and royalty income. Concluding a highly successful 1871 , she received the Royal Legion of Honor from Queen Victoria.
Knight continued her inventive activity for the next four decades. Her patents included: upgrades to the paper bag machine, a skirt protector, a spit or rod for cooking food, machines for cutting soles for shoes, a clasp for robes, a numbering machine, a window frame and sash and improvements for rotary engines.
By the 1880s, she had moved back again to Massachusetts, settling in Ashland and then Framingham. She established a laboratory in Boston where she worked on many of these aforementioned pursuits, accepting royalties in payment.
Throughout her life, she amassed about 30 patents in total, an impressive feat as she had no technical training. Margaret Knight, unmarried, died on Oct. 12, 1914 from pneumonia at 76 years of age. She was buried in Newton, Mass.
Edward T. Howe is Professor of Economics, Emeritus, of Siena College near Albany, N.Y
Images: Colorized image of Margaret Knight created by ChatGPT.


























