I'm always happy to look at specific topics in response to requests, although the result may be no more than a jumble of citations. This current post is in response to an interest in Gilded Age San Francisco.
The “Gilded Age” covers roughly the last quarter of the 19th century and, as a historical period, refers specifically to the United States. This bibliography ranges a bit farther afield, however, taking in English sources as well, to provide a broader cultural context. (And because I don’t have as many US-specific works.) None of these sources specifically address the west coast, though there is western material in several of the general studies. Lillian Faderman has some excellent and detailed studies of California lesbian culture in the 20th century, but none extends far enough back to be relevant here.
There is undoubtedly much more material available than this, especially if one digs through the bibliographies of these publications. Since my own interests tend to fall earlier than this period (and tend to be more focused on Europe), I haven't done as much follow-up from these general works. Some of the works cited below have been covered in detail by the Project, so check the index for more details.
Donoghue, Emma. 2010. Inseparable: Desire Between Women in Literature. Alfred A. Knopf, New York. ISBN 978-0-307-27094-8
Coverage of the late 19th century appears across several of the theme-based chapters. This study looks specifically at portrayals of lesbians in literature.
Faderman, Lillian. 1981. Surpassing the Love of Men: Romantic Friendship and Love between Women from the Renaissance to the Present. William Morrow and Company, Inc., New York. ISBN 0-688-00396-6
A somewhat dated, but still valuable general study. Scholarly and well-footnoted but aimed at a general audience. The chapter on the 19th century comprises about one-third of the book
Faderman, Lillian. 1999. To Believe in Women: What Lesbians Have Done for America - A History. Houghton Mifflin Company, New York. ISBN 0-395-85010-X
A series of biographical studies covering the later 19th and very early 20th century. Women who were politically and socially active and whose personal lives were instrumental in motivating their activism.
The History Project. 1998. Improper Bostonians: Lesbian and Gay History from the Puritans to Playland. Beacon Press, Boston. ISBN 0-8070-7948-0
Biographies of both the famous and non-famous, copiously illustrated when possible. Substantial material from the later 19th century, the heyday of “Boston Marriages”.
Rupp, Leila J. 1999. A Desired Past: A Short History of Same-Sex Love in America. The University of Chicago Press, Chicago. ISBN 0-226-73155-3
Much like her book Sapphistries in its anecdotal survey format, but focused specifically on the U.S. and not restricted to women. Relatively little material in the target period, but a few very detailed anecdotes and biographies.
Marcus, Sharon. 2007. Between Women: Friendship, Desire, and Marriage in Victorian England. Princeton University Press, Princeton. ISBN 978-0-691-12835-1
A study of close relationships between women in the second half of the 19th century, ranging from friendship to marriage-like permanent relationships. Somewhat dense and very scholarly but incorporating a great deal of primary material.
Oram, Alison & Annmarie Turnbull. 2001. The Lesbian History Sourcebook: Love and Sex Between Women in Britain from 1780 to 1970. Routledge, New York. ISBN 0-415-11485-3
This sourcebook is organized thematically, with three main sections: lesbian archetypes, professional commentaries (medicine, education, and law), and cultural contexts. Within those sections, the entries are organized chronologically. Only about 16 entries fall within the second half of the 19th century.