Who were the pioneers of editing, what were their contributions to film editing,

Who were the pioneers of editing, what were their contributions to film editing, how important were these techniques to the future of film, who was in competition? What was editing for cinema and how quickly did it evolve. What did these contributions in editing mean to Film as a whole.
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People that should be mentioned and heavily talked about include, but not be limited to, Edwin S. Porter, D.W. Griffith, James Williamson, Georges Melies, and Sergei Eisenstein
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Stay between film industry and film editing during years between 1894 and 1945