I have at long last completed cataloging the known portions of the Mather Family Library at LibraryThing. This turned into one of those projects that once begun was rather more expansive than it first appeared, so it took longer than I expected to finish, but I think it came out well in the end.
The library contains copies of books owned by several members of the Mather family, from patriarch Richard to Increase and Cotton (at left), their cousins and nephews, sons, daughters and grandsons (the notorious Boston loyalist minister Mather Byles) and several other relations. The books are now widely scattered, although the majority of them are currently housed at the American Antiquarian Society in Worcester, MA. The MHS and BPL also hold portions of the collection.
Many if not most of the books contain ownership inscriptions, which are noted for those where either the old bibliography (from 1910) or the current library records contain them. The copies at MHS have been examined personally and verified, but the others I haven't physically looked at yet.
Not surprisingly, the Mathers don't share many titles with modern readers (or at least LT-users, I'm sure there's somebody out there with a few obscure 17th century religious pamphlets). Those they do share are ones you might expect: Machiavelli's The Prince, Thomas Browne's Religio Medici, Ovid, Descartes, Plutarch, &c. No Shakespeare for this lot, of course.
This is the first time (so far as I know) that the entire known collection of the Mathers (there may be a few more scattered titles out there - if anyone knows of such, please let me know) has been compiled in one place: the 1910 bibliography did not include a large portion of those held at AAS; those are included here, and all records have been updated to the extent possible.
An interesting look, I think, at the bookshelves of the most important early New England divines.