This chapter explores interactions among sexual scientific models of homosexuality in the late nineteenth and early twentieth centuries, and their uses in American fiction during the same era. The medical framework had a less pervasive influence than the historical research sometimes suggests. Queer-inflected writing in the U.S. between the 1880s and the 1930s features a varied cast of characters, ranging from winsome youths who fall under the spell of an older, trollish brute; to tortured souls striving to understand themselves and to be understood by others; to enigmatic figures who charm and fascinate everyone around them without offering much in return; to fey, frantic queens who’ll do anything for a laugh. Many of these characters might be taken as expressions of a queer, and even specifically homosexual, identity—but they often bear few if any signs of medicalization unless we contend that all identity-based conceptions of sexuality are necessarily rooted in a medical framework. If we ask what the concept of medicalization contributes, such that it helps to make sense of these works, one answer is that the medical case history, in particular, exhibits generic features that queer fiction borrowed, imitated, satirized, questioned, challenged, and sometimes ignored.