In part, insists Sandweiss, we are all social creations. She makes this argument extraordinarily well, in a sophisticated work of scholarship. There are only a few places where I wished she had pushed a little harder on received ideas: for example, King’s attraction to what his friend Henry Adams called “the archaic female, with instincts and without intellect.” We wince now at such a description of women of color. But this stereotype was deeply embedded in American culture, and I would have liked Sandweiss to tease it out a bit more.

On a similar note, the author describes “slumming” as a century-old sport of the middle class. But how did this search for authenticity among the poor, and often non-white, relate to fantasias about women of color? And how did both of these cultural constructions relate in turn to something like minstrelsy, the popular entertainment of the day in which whites (and sometimes blacks) covered their faces in burnt cork and trafficked in a dizzying assortment of racial stereotypes?

Minstrelsy might seem like a bit of a departure from the narrative. But surely passing as black, even with the most respectful of intentions, has something in common with the practice of blackface. In any case, these caveats are a testament to the broad and deep resonance of Sandweiss’s story, which sets the mind whirring, even as we continue to struggle with fundamental ideas about race and culture.

Passing Strange is not only a lesson in the intricacies of class, race, and gender relations. It also demonstrates how to write a particular kind of history—how, that is, to reconstruct lives in the absence of historical records.

This absence is glaring in the case of Ada Copeland, whose very birth was never recorded. Yet it also exists, albeit more subtly, in King’s life. Sure, Clarence King was a public figure with a generous paper trail, but what of James Todd? The great care King took to obscure that part of his life reverberates down the years, so that even an assiduous researcher (take a look at the rigorous footnotes) finds only small shards of information.

And so Passing Strange is dotted with lacunae, many of them marked with such phrases as, “No anecdotal stories from Ada’s own childhood survive,” or “It is not entirely clear just how Clarence King’s double life began.” Sandweiss fills in at least some of these gaps with careful speculation. In other words, she takes us to the point where facts disappear, and then offers well-researched possible scenarios. (It’s the research, and the disavowal of omniscience, that divides the historian from the novelist.)

The larger point, though, is that society, and thus history, values certain lives over others. Some are chronicled in newspapers, biographies, and archives; others pass into obscurity. The challenge to the present-day historian is to resurrect as much as possible of those rich, yet undervalued lives—and in Passing Strange, Sandweiss more than rises to the challenge.

Elinore Longobardi is a Fellow and staff writer of The Audit, the business-press section of Columbia Journalism Review.