When the peace settlement with Mexico was pending, a bill to authorize the rectification of boundaries by the purchase of a large territory from Mexico was presented in Congress. Mr. Wilmot of Pennsylvania, in 1846, moved as an amendment a proviso--known in history as "The Wilmot Proviso"--stipulating that slavery should never be permitted in any of the territory to be thus acquired.
This additionally intensified the controversy, and while the Wilmot Proviso, though adopted by the House of Representatives, was rejected by the Senate and never became law, its suggestion and the House's adoption of it were accepted by the South as an additional evidence of the uncompromising hostility of the anti-slavery party, and of a determination at the North to use the Federal power for the limitation, the restriction and the ultimate extermination of slavery.
In the meantime a sentiment against abolitionism had grown up at the North which was implacably intolerant of opinion. Owen Lovejoy was put to death by an Illinois mob for his offense in publishing an aggressively abolitionist newspaper. Other men suffered persecution upon similar account. Newspaper offices were wrecked and their proprietors sorely dealt with by mobs in states which by their organic law forbade slavery and the people of which had no interest in the institution. They regarded all abolitionist movements as agitations seriously threatening the Union and recklessly risking the public peace. They were ready to resort to mob violence by way of repressing activities which they regarded as destructive of public order and seriously menacing to the Union, which had come to be an object of adoration to the great majority of Americans.
Thus the controversy involved violence and lawlessness at the North even more than at the South.
Again the anti-slavery propagandists at the North were men of shrewd intelligence as well as men of profound convictions as to the absolute righteousness of their cause. They believed without doubt or question that anything which might help to destroy slavery was right. To that end they were ready to violate law, to commit acts which the law--improperly as they thought--denounced as criminal, and even to destroy the American Republic if by that means they could extirpate the system of human bondage. They were devotees of a cause that admitted of no compromise or qualification. They were crusaders at war who regarded all means as righteous that might lead to what they believed to be a righteous end. This is not the place in which to question the correctness of their belief or to criticize their conduct. Our concern is merely to record the facts and trace the consequences of them.