How did women in early modern England protect their investments in copyrights and realize profits from them? This new study explores the ways that women who owned copyright sought to turn manuscripts into money and protect their investments in intellectual property for themselves and their posterity. Through an analysis of previously unpublished archival sources and a new examination of print sources, this study shows that women copyright proprietors contributed to the establishment of copyright as a sellable commodity at a time when it was still undefined. Women Proprietors of Copyright charts a new history of copyright and women’s labor in the book trade at a crucial period of its development.