Then set in with full vigor the controversy over the new territory which Calhoun had foreseen. Calhoun had been left in a sort of isolation by his defection from the administration upon the war, but he did not break with President Polk; for the reason, says Von Holst, that he wanted to save his influence to oppose the tendency to a war with England. Oregon had been held in joint occupancy by the two nations for many years; now a line of demarcation was to be drawn, and there was a loud popular demand for maintaining at any cost the extreme northern line of latitude--it was "Fifty-four-forty or fight." But the sense of the country was against coming to extremities, and Calhoun--a statesman when slavery was not concerned--threw his influence with the moderate sentiment which secured the acceptance of the line of 49 degrees. But he looked with foreboding eyes on the deepening conflict of the sections and the advantage which gravitated toward the North;--from political causes, he declared, unwilling or unable to recognize that the industrial superiority lay inevitably with free labor. He met the danger with a bolder and more advanced claim. The South, he declared, had had enough of compromise over territory; it must now fall back on its ultimate right under the Constitution; and that right was that slaves, being lawful property, might be taken into any territory of the United States, and Congress had no right to forbid their introduction; neither had Congress a right to refuse admission of any State whose people desired to retain slavery. This was a claim for the nationalization of slavery; and it was not until after Calhoun's death that the South came to this position, staked its cause upon it, and when it was rejected by the popular vote broke with the Union. But Calhoun's logic and passion had not yet brought his section up to his own position, and over the division of the newly acquired territory North and South disputed as before. While the war was still waging, President Polk asked for an appropriation to be expended as compensation for new territory; and David Wilmot, a Democratic member from Pennsylvania, moved that a proviso be added, stipulating that from any new territory acquired by purchase slavery should be excluded. This was passed by the House, but rejected by the Senate. The Senate was long the stronghold of the South, the States having an equal representation, while in the House the greater increase of free State population gave them a fresh advantage at each new census and apportionment. The "Wilmot proviso" was for some years the watchword of the anti-extensionists. To the typical Northerner, it seemed monstrous that slavery should be introduced by law in territory where it had no previous existence. To the typical Southerner it seemed no less unjust that his peculiar institutions and usages should be excluded from the common domain, for which his section had paid its share of money and more than its share of blood.