For most of the nineteenth century, newspapers in the United States were heavily partisan. Newspaper editors sat on party central committees, and they tailored their matter to promote a party line. Most of their news was copied directly out of other partisan newspapers, which editors exchanged for free through the mail. A typical editor with 500 or 800 subscribers might exchange with as many as a hundred other newspapers throughout the country, passing on bits of information and opinion from all of them and hoping that they too copied items from his or her paper. This party press system was remarkably open ended. Items could enter from any point, although they had to fit within the boundaries set by the agendas of the major political parties.

One issue that the major parties tried to keep out of the papers was slavery. Because they relied on votes...