From a very young age, American Margaret Knight (1838-1914) liked to build things. She came up with her first invention when she was just twelve years old!
Later, as a young woman, she invented a machine that could efficiently cut, fold and glue a piece of sturdy brown paper into a flat bottom bag. At the time, she worked in a factory that produced envelope style paper bags and thought how much easier it would be to pack things if the bag had a flat bottom. So she set out to design a machine that would make such a bag.
Margaret built a wooden model of the machine, but needed a working iron model to apply for a patent. Charles Annan, who was in the machine shop where Margaret’s iron model was being built, stole her design and patented the device. Margaret filed a successful patent interference lawsuit. In his defense, he claimed that there was no way that a woman could have developed such a complex machine. She used her notes and sketches to prove otherwise, and she was awarded the patent in 1871. Margaret found a business partner, and together they established the Eastern Paper Bag Co. She went on to invent many other things, and received 87 patents for other inventions.