While the stories Americans tell about the Civil War have evolved over the past 150 years, there is little debate among historians today that it was fundamentally a struggle over the future of slavery. And yet, many continue to frame it as a story about states' rights, or a failure to compromise, or core values like honor and dignity. On the Civil War's centennial, Robert Penn Warren wrote that the war is "our only ‘felt’ history–history lived in the national imagination.” It seems that he may have been right.