When Abraham Lincoln's election in 1860 prompted several Southern states to secede, the North was sharply divided over how to respond.

In this groundbreaking and highly praised book, McClintock follows the decision-making process from bitter partisan rancor to consensus. From small towns to big cities and from state capitals to Washington, D.C., McClintock highlights individuals both powerful and obscure to demonstrate the ways ordinary citizens, party activists, state officials, and national leaders interacted to influence the Northern response to what was essentially a political crisis.

He argues that although Northerners' reactions to Southern secession were understood and expressed through partisan newspapers and officials, the decision fell into the hands of an ever-smaller group of people until finally it was Lincoln alone who would choose whether the future of the American republic was to be determined through peace or by sword.