Here’s a good research resource which I hadn’t come across before (and should have). New York State Archives has the largest collection of film scripts in the world, some 53,000. It makes available a database of its script index, covering the period 1921-1965 (it advertises itself as covering 1927-1965, but I’ve found records going back to 1921). This doesn’t give you the script itself, just the bare outlines of the production details, but these are more than valuable enough in themselves.
Each record gives you (and is searchable by) original title (there are many non-American films listed), title in English, country, year, writer’s last name, director’s last name, alternate film title, manufacturer, and exchange. The Motion Picture Commission began its work in 1921, but tragically almost all of the 18,000 scripts for silent films that passed through its hands are now lost. However, the outline records are still there, and form a hugely useful reference source by themselves, and for a lot of these titles the archives have associated documentation, but not the script itself.
The collection exists because, for forty-four years, New York state censorship required distributors to submit scripts for vetting, so anything exhibited theatrically in New York between 1921 and 1965 is going to be there. The archive also contains the apparatus of state film censorship – applications for licences, reviewers’ reports, notices of change in title or length etc., as well as the scripts. Scripts only start to be available from 1927. Frustratingly, there doesn’t seem to be any way to search on extant scripts for silent films. Nor can you combine search requests, so you can’t automatically look for all Walt Disney-produced films in 1924, for example. Minor gripes apart, this is a major gateway into the films of the 1920s.
It’s possible to order copies of scripts, if you are the copyright owner, or have the permission of the copyright owner, or can claim copies under a ‘fair use’ declaration. It may also be that you have to be a United States citizen – it’s unclear.