The grocery bag's neat, boxy base was once a hard mechanical problem—and a man tried to claim the solution.
Margaret E. Knight designed a machine that could cut, fold, and paste flat-bottomed paper bags, She began developing it while working at a Massachusetts paper-bag company around 1867. After more than two years of work, she had a wooden prototype and hired a machinist to build a working model for a patent application.
Before it was finished, the machinist, Charles Annan, filed for the patent himself. Knight challenged him with drawings, notes, diary entries, and witnesses. Annan reportedly argued that a woman could not understand such machinery; Knight answered by explaining its parts and operation in detail. The Patent Office awarded the patent to her in 1871. Knight later held more than twenty patents.
A familiar paper bag carries an overlooked story of engineering skill, persistence, and a fight to have the inventor's name recognized.