Empire of Print offers a fresh account of evangelical power by uncovering how the American Tract Society (ATS) leveraged print media to spread its message across an expanding nation. One of the era's largest media corporations and a pillar of the benevolent empire, the ATS circulated some 5.6 billion printed pages between its founding in 1825 and the eve of the Civil War. It wasn't just the volume of materials that mattered—it was the sophisticated media infrastructure that evangelicals developed for their message to reach readers, coast to coast. Media infrastructure refers to the material assemblages that work below the surface of media content, including the format of publications, the avenues of their movement, and the circumstances surrounding their reading. As a non-coercive yet effective form of power, infrastructure shaped how, when, and why readers engaged with evangelical texts. While showing how the ATS became a formidable force in American society during the nineteenth century, Empire of Print opens larger questions about the entanglements among people, things, texts, and institutions, the dynamics of power in a media-saturated world, and the salience of race, class, and region in the distribution and reception of media.