There had grown up at the North an intolerance of slavery which freely expressed itself in denunciation of those who supported or countenanced the institution. There had grown up at the South a sentiment in advocacy of slavery such as did not exist in that region in the earlier years of the Republic. Men whose fathers and grandfathers had diligently sought means by which to free their native land of a curse, had little by little come to regard that curse as a blessing. Men whose forefathers had regarded slavery as an inherited misfortune, came to regard the institution as right in itself and to defend it as the best, most generous, and most humane labor system in the world. In support of this contention they could point to the factory system of old England, and New England and argue with some truth that nowhere in the world was labor so generously rewarded as at the South. Moreover, the antagonism to the system which had developed at the North had its very natural reflex effect. The offensive terms in which slave owners were habitually spoken of in Northern prints were well calculated to impel Southern men to the angry and intemperate defense of their system. Still more effective in breeding a "thick and thin" pro-slavery sentiment at the South were the aggressive measures taken at the North for the annoyance of those who held slaves. The laws for the rendition of fugitive slaves--not at that time so strict as they were afterwards made--were habitually set at naught. There existed a fairly well organized system called "the underground railroad" by which slaves were induced to run away and by means of which their flight was facilitated. All this was dictated by a profound conviction on the part of those who engaged in it that slavery was an institution so utterly wrong that any means by which its hold could be impaired were right in morals, no matter what the law might say. All this was done in defiance of law, in violation of the statutes and in flagrant disregard of that compact of reciprocity upon which the Union was founded. We are not concerned in the twentieth century to discuss the question of the right or wrong of men's conduct in the first half of the nineteenth. But if we would understand the irritations that bred the war between the North and the South, we must recognize not only all the facts but equally all the refinements by which they were judged in their time.