Margaret E Knight

The most prolific 19th-century female inventor with 87 patents

Margaret Eloise Knight (1838–1914) earned the nickname 'Lady Edison' for her extraordinary mechanical innovations that transformed industrial manufacturing. Her 1871 paper bag machine patent revolutionized packaging and remains foundational in grocery stores worldwide.

Knight's engineering career began at 12 when she developed a shuttle-restraining device for textile mills after witnessing a fatal accident. Her most famous invention automated the production of flat-bottom paper bags through a complex series of blades, folders, and side-welters - technology still used in modified form today.

Despite facing patent theft attempts and gender discrimination, Knight secured 27 patents across diverse fields including shoe manufacturing, rotary engines, and window frame designs. Her 1884 dress shield patent demonstrated particular commercial success, generating over $25,000 annually (equivalent to $700,000 today).

The Smithsonian preserves her original bag machine model, while the National Inventors Hall of Fame recognizes her as America's first professional female inventor. Knight's legacy paved the way for future generations of women in STEM fields.