To explore how historians grapple with the sexual identity of their subjects, this article reflects on the research process for a biography of prison reformer Miriam Van Waters. It reviews three kinds of evidence that combine to shape an interpretation of Van Waters' sexuality: first, authoritative discourses she encountered and may have internalized or modified; second, personal sources such as letters and diaries that provide clues to her subjective experience of sexuality; and third, rumors, accusations, and assumptions that entered the historical record. While affirming earlier insights that we cannot depend on either labels or direct evidence of sexual behavior to locate the subjects of lesbian history, this article also argues for historical specificity about the meaning of sexual identity and an appreciation of the ways that class and race can take precedence over sexuality as a source of identity.