I think there is a bit of revisionism in this editorial.  It stresses slavery as the cause of the civil war.  It was a factor, but so were states rights.  The South was not the first area of the United States to consider secession.  During the war of 1812 areas of New England talked about leaving the Union because they disagreed with the war with England at a time that England was fighting Napoleon.  It is worthy of note that Abraham Lincoln wrote a New York newspaper in 1862 and said " My paramount objective in this struggle is to save the Union, and is not either to save or to destroy slavery."