Here’s an amazing data set: Miriam Lahrsow’s Self-Annotated Literary Works 1300-1900: An Extensive Collection of Titles and Selected Metadata.
The Introduction to the Collection (PDF) explains what it is and why she made it:
This collection was created in the context of my PhD thesis titled The Author as Annotator: Ambiguities of Self-Annotation in Pope and Byron (Eberhard Karls Universität Tübingen, 2021, GRK 1808 “Ambiguität”, DFG- Projektnummer: 198647426). It lists more than 1100 literary works published between 1300 and 1900 that feature self-annotations, i.e. marginal notes, footnotes, or endnotes written by the author of the work. Self- annotations here only refer to notes that were published in a work, not private, handwritten comments in the author’s own copy.
The aim of this collection is threefold. First of all, it shows the prevalence and variety of literary self-annotation before 1900. While authorial notes in post-1900 literature have received a considerable amount of critical attention, the number and ‘experimentality’ of earlier self-annotations is often underestimated among literary scholars. The present collection strives to correct this view. Secondly, the collection reveals general tendencies in the field of literary self-annotation, providing tentative answers to questions like ‘when did it become popular to use both footnotes and endnotes in the same work?’. Thirdly and most importantly, this collection is meant to provide an incentive and starting point for further research by laying the (albeit yet insufficient) groundwork for quantitative research, by including a multitude of now-forgotten works, and by citing relevant secondary literature on as many titles as possible.
It’s mostly focused on English poetry from 1700–1830, but there’s a lot else in it. She generously cites my Fictional Footnotes and Indices page, which as she notes is mostly post-1900 work, and also Bernhard Metz and Sabine Zubarik’s Noten, Anmerkungen, Kommentare in literarischen Texten, which was new to me.
The data is available in XML (and as an Access database, if you run Windows) and human-readable as PDF or HTML. Obviously it took a huge amount of work to assemble this, and it’s delightful that it’s now available online. This is just the kind of digital humanities I like to see. Lahrsow has done marvellous work!