I want to read On Pilgrimage by Dorothy Day and the library doesn't own it - I even searched on interlibrary loan. But I can't suggest this
Interlibrary loan is indeed the perfect opportunity to read older titles. The book you mention is held by many other libraries and would not be difficult to obtain. Click on the interlibrary loan link and then on "search and request" at the top of the page; once you find your item, you will see a "request" button in the record, which will generate an online form that goes to our interlibrary loan department. The only cost is the postage to send the item back to the lending library.
Let me know if you have any questions, or any trouble with the process; I will be happy to walk you through it!