More on Paper Bags and Paper Goods • The History of Paper Bags or Sacks The use of sacks only really started to take off during the Industrial Revolution: between 1700 and 1800. • Paper and Papermaking The history of paper, papermaking and paper sacks; the inventors and innovations behind the different processes.

Related Innovations • Women Inventors

Margaret Knight was an employee in a paper bag factory when she invented a new machine part that would automatically fold and glue paper bags to create square bottoms for paper bags. Paper bags had been more like envelopes before. Workmen reportedly refused her advice when first installing the equipment because they mistakenly thought, "what does a woman know about machines?" Margaret Knight can be considered the mother of the grocery bag, she founded the Eastern Paper Bag Company in 1870.

Margaret Knight (Mattie) was born in 1838. She received her first patent at the age of 30, but inventing was always part of her life. Margaret or ‘Mattie’ as she was called in her childhood, made sleds and kites for her brothers while growing up in Maine. When she was just 12 years old, she had an idea for a stop-motion device that could be used in textile mills to shut down machinery, preventing workers from being injured. 

Margaret Knight is considered one of "the female Edison," and received some 26 patents for such diverse items as a window frame and sash, machinery for cutting shoe soles, and improvements to internal combustion engines. Margaret Knight's paper bag machine made flat-bottomed paper bags that are still in use to this very day!

A few of Margaret Knight's other inventions:

dress and skirt shield  - 1883

clasp for robes  - 1884

spit - 1885

numbering machine - 1894

window frame and sash - 1894

rotary engine - 1902