Marvelous Mattie: How Margaret E. Knight Became an Inventor

With her sketchbook labeled My Inventions and her father's toolbox, Mattie could make almost anything – toys, sleds, and a foot warmer. When she was just twelve years old, Mattie designed a metal guard to prevent shuttles from shooting off textile looms and injuring workers. As an adult, Mattie invented the machine that makes the square-bottom paper bags we still use today. However, in court, a man claimed the invention was his, stating that she "could not possibly understand the mechanical...