re: Do you think the Civil War was started over slavery?

I think Alexander Stephens' speech is representative of the views of the Southern political leadership. He wouldn't have occupied such a high post if he was out of step with the rest of the Confederate state.

Now as to the combat motivation of the men in the ranks in the army, who mostly didn't own slaves, they served for a variety of reasons. Just like our fighting men and women today.

I recommend Bell Irvin Wiley's "Johnny Reb" book for anyone interested in how Southern soldiers viewed the war.