We study copyright law and its relationship with cultural conceptions of authorship and technical constraints on the economics of publishing in the US. Because American copyright law was first developed in the eighteenth and nineteenth centuries, we focus on that time period. And because magazines were the primary forum for literary expression in America during this time, we study the magazine industry. Both technical and cultural factors created opportunities for magazines and imposed constraints on them, but most effects of copyright law were mediated by cultural, not technical, factors. Lack of copyright protection for foreign authors allowed magazines reprint foreign authors’ work for free. However, copyright law was not used by magazines to protect domestic work: very few claimed copyright over the original material they published and none of those claims were adjudicated by courts. Therefore, magazines reprinted work from domestic sources, including other magazines. Nevertheless, copyright law had constitutive effects on the literary market: it spurred the emergence of a cultural conception of the author-as-paid-professional; in turn, this cultural shift fostered the market for literature, as magazines began to pay authors for their work and compete intensely over the work of the most popular authors.