New media and new applications of existing media are typically seen as ways of distributing knowledge more effectively, often with hopes that this process will strengthen democracy. Adopting a history-of-knowledge approach, the authors analyze methods of knowledge circulation attending early print, nineteenth-century mechanics’ institutes and public libraries, early radio broadcasting, and explanatory journalism, providing a comparative historical framework for a recent new-media platform for distributing knowledge, The Conversation network. Appealing to a socially broad audience has consistently been a challenge. Efforts to distribute knowledge also reflected differences in prevailing media ecosystems, national systems of political economy, and contemporary social/political concerns.