I think the most accurate take on pre-civil war attitudes towards abolition etc is by Robert Penn Warren in his book The Legacy of The Civil War. In his 'treasure of virtue' idea he does a great job of demonstrating the shift in mindset that obliterated the old one and paved over its remains with a new one.

If you haven't read that book I think it's the single best book to read in connection to understanding the Civil War and its impact on America's psyche. It's really short anyways.

The Great Alibi and Treasure of Virtue perfectly encapsulate the two ideas that have crippled discussion regarding the war ever since it ended.

You can probably pick up a copy for $10-15 on Amazon.

Honestly, in today's highly politicized and racially charged world it's almost difficult to discuss the topic having not read it. It should be required reading in High Schools across the country.