Volume III (1876-1900) of Lyle Wright's "American Fiction" would be a place
to start looking. Tedious to do, but just sitting down and scanning the
titles and the brief notes under most of his entries might uncover some
untrodden ground. Since Wright lists every book of fiction (both novels and
short stories) by an American author of this period, you'd have great
coverage, but the weakness is that Wright doesn't provide very good notes
for anyone seeking themes, characters, or motifs, although he's so-so when
it comes to genres. Still, with Wright in one hand and a mouse pointed at
google in the other, you'd be ready to rumble.  Maybe point that mouse at
vivisimo since they have very useful "clustered" search results perfectly
suited to this kind of enquiry

Kevin Mac Donnell
Austin TX