At the beginning, Thirty Years of Motion Pictures (The March of the Movies) was merely a presentation/lecture given by Otto Nelson at two National Board of Review conferences, in 1925 and 1926, under the title Early History and Growth of the Motion Picture Industry. These proved so successful that work on a film version began, with historian Terry Ramsaye (who around the same time published the seminal study A Million and One Nights: A History of the Motion Picture) coming onboard the production.
