Studies of antebellum political behavior tend, quite naturally, to focus on patterns of partisanship that helped to provoke the Civil War. Such studies have painted a clear picture of antebellum ideology, party organization, the sources of partisan allegiances, political realignment, the emergence of the slavery issue, and the deepening sectional crisis. When I began this examination of popular political life in antebellum Ohio, however, I wanted to look first at patterns of participation, establishing the outlines of Ohio's eligible and active electorate, before moving on to an analysis of partisan issues and behavior. Initially, that task seemed simple and straightforward. Traditional interpretations of political participation on the eve of disunion had emphasized the liberality of the franchise after a generation of suffrage reform, especially in the North, unequaled rates of voter turnout, and the aggressive commitment of political parties to mass participation.

In fact, the foundations of political participation in antebellum Ohio proved far more complex than this traditional framework had led me to expect. Near the beginning of my research, I came across poll books – individual-level records of voting – and I tried to link them to the U.S. census to determine the social, economic, and ethnic sources of popular participation. The results were troubling. To my surprise, most of the voters recorded in the poll books were not listed in the U.S. census: they were migrants. This unexpected discovery led me to a vast literature in social history dealing with the often surprising geographical mobility of nineteenth-century Americans.