I admit that I might not have recognized part of your premise -- that civil war might have been avoided -- until reading Ayers. Some years ago that premise formed the common foundation of Civil War histories written by Avery Craven, James G. Randall and Allan Nevins.
Page 35 of A Companion to 19th-Century America (2006) by William L. Barney provides a summary of this position and why it has fallen out of favor among historians.