I spoke with the librarians at Mina Rees, and found this great tool, ArchiveGrid. It helps you find archives.
I’m attaching the link here: http://beta.worldcat.org/archivegrid/, but if that doesn’t work, here’s how I found it.
Go to the Mina Rees homepage (CUNY GC library), and click on the database tab (right above the box where you’d search for books, articles, &c.). Look under the A databases and click on ArchiveGrid. Voila!
ArchiveGrid will search for archives by city and subject. It’s already been helpful for me.
Have a great day and don’t forget to vote!
All the best,