Friday, October 17, 2014. Osbourn Dorsey Invented the Doorknob and Doorstopper. Ever since the first door was created, it is likely that human beings have understood how to use an object or device to keep it open. Heavy stones or bricks or metal cans or chunks of wood all work to prevent a door from closing. Mr. O. Dorsey was a 19th century African-American inventor.