In 1870, Margaret Knight invented a machine that automatically cut, folded and glued flat-bottomed paper bags. Her machine revolutionized the paper bag industry. Before Knight’s invention, machines could only make envelope-style paper bags, which were limited in what they could hold. Flat-bottomed bags were handmade and considered an artisanal item. Knight founded the Eastern Paper Bag Company in1870 with her machine, which was adopted worldwide. An updated model was still in use until the end of the 20th century.
Knight, who is frequently recognized as the first woman to receive a U.S. patent, designed her first invention at 13 years old while working in a textile mill after seeing many of her coworkers injured on looms. Knight created a shuttle restraint system that became a standard safety device. She never considered patenting her early ideas. Eventually she saw the moneymaking potential of her inventions, but it took a court battle to defend her flat-bottomed bag machine from a man who claimed that a woman "could not possibly understand the mechanical complexities” before she received her first patent. From1870 to 1915, Knight invented more than 100 machines and received 26 patents. She is one of the most notable inventors of the 19th century.