Crossdressing has a long and rich history with clear relevance for trans studies. Across centuries and over continents, countless individuals have engaged in crossdressing to communicate desires, identities, and ways of being that challenge fixed binary gender. Crossdressing practices are diverse, however, with multiple cultural meanings that historians need to carefully explore. This entry examines the complexity of crossdressing as a concept, the range of crossdressing practices in history, and efforts to police crossdressing in the 19th- and 20th-century United States through crossdressing laws.