Margaret E. Knight

Margaret Eloise Knight (1838 to 1914) was an American inventor, notably of a machine to produce flat-bottomed paper bags, and has been called the most famous woman inventor of the nineteenth century. Born in York, Maine, she moved with her widowed mother and brothers to Manchester, New Hampshire, and left school at twelve to work in the cotton mills, where she devised a safety device for a loom after witnessing an accident. In 1867 she joined the Columbia Paper Bag Company in Springfield, Massachusetts, and in 1868 invented a machine that cut, folded and glued paper into the flat-bottomed bag. When a machinist patented her design first she won a patent interference suit in 1870 with her drawings, journals and witnesses, received her patent in 1871 and founded the Eastern Paper Bag Company. She went on to hold at least 27 patents, covering paper feeding machines, shoe cutting machines, a numbering machine, a window frame and parts for rotary engines, and lived on royalties and patent sales.