Stop motion was a method of animating objects for films. This would require lots of pictures of the object with slight changes between each frame. When played, the moving frames would create the illusion of movement from the object. The first ever stop motion film was the Humpty Dumpty Circus (1898) created by James Stuart Blackton and Albert Edward Smith. Blackton continued working with stop motion to create The Enchanted Drawing.
Video: The Humpty Dumpty Circus
Mainstream Film Making
Stop motion's first serious entry into main stream film making was The Lost World (1925) by Willis O'Brien, which became very popular. The film featured stop motion animation mixed in with real life actors. Willis O'Brien continued developing his techniques until he made the movie, King Kong (1933) by then, he had fixed many of the flaws of his previous work The movie had smoother motion, more realistic expressions and better use of stop motion mixed with real life acting.