Here's the thing about librarians: they are the only people I know who are incredibly excited TO DO YOUR WORK FOR YOU.
I'm starting a very cool book project with fellow Berkman Fellow Dennis Tenen examining how we can encourage doctoral students to openly license and publish their theses, how we can turn the dissertation submission process into a teachable moment for Open (more on that in the future).
We decided a historical perspective might help, so I emailed my favorite reference librarian, who immediately connected me with two archival librarians. As per usual, they were completely awesome. Harvard has a fairly complicated set of archives divided between onsite physical materials, physical materials in repositories, and online materials. Within hours of receiving my question, an archival librarian had found the most relevant materials immediately available in the archives, identified bibliographic records for me to examine when I came into the library, and emailed me this information, directing me to an exact document perfectly relevant to my interests:
You'll find some of the information you're looking for in Harvard catalogues. Pre-1923 catalogues are available on line. Here's a quick link: http://fig.lib.harvard.edu/fig/?bib=000137075
(For an example of information directly relevant to your inquiry, see page 589 in the 1914/1915 catalogue.)
When I went into to visit, she also had some useful knowledge off the top of her head; for instance, she happened to know that Harvard started submitting archival copies of theses with UMI in 1982. It would have taken me an hour of triangulating through policy documents to figure that out.
As online resources become more complex, we need wise humans to help act as guides. Librarians know how to do that better than you do. Ask them for help. They also, typically, are warm, curious, helpful people.
For any doctoral students out there thinking of starting a new research project, I strongly encourage you to make your university reference librarian your first stop. I've had great luck with municipal librarians and with government archivists as well.
It takes a village to raise a research project.