Early-day films were created by a company by Thomas Edison, who is famously known as an American inventor who developed ideas such as the phonograph, the light bulb and the motion picture camera. The films consisted of one long static shot, which was locked down throughout the film. At this stage in development, the idea of story and editing didn't exist, and films lasted as long as there was film left running in the camera.
In 1899, development started when Edison hired Edwin Porter and put him in charge of a studio in New York, and Porter is known to be one of the very first to experiment with the idea of film editing.
The first film to have a breakthrough in regards to having a narrative, action (and even a different shot - a close up of a hand as it pulls an alarm) called Life of an American Fireman. For inspiration and guidance in creating this film, Porter followed early films created by Georges Méliès.
As time passed, it was known that Porter continued to experiment with the idea of film editing by using different cinematic techniques and later went on to discover the idea and important aspects of language in motion pictures: 'that the screen image doesn't need to show a complete person from head to toe and that splicing together two shots creates in the viewer's mind a contextual relationship'. - this was known tot be one of the most important discoveries which made all non-live narrative films, as well as television programs possible - the idea that you can use different shots (shot in a variety of locations over different lengths of time to create an overall narrative.