If the Whigs had nominated Webster that May, on a platform opposing both annexation and disunion, they would have gained more votes at the North than they would have lost at the South. They might possibly have carried that election; and their strength in the Border States would have enabled them, sooner or later, to check the extension of slavery without bringing on civil war. Their platform was silent about Texas, as well as about the Union; their chief candidate, Clay, had already made compromises in the interest of the South in 1820 and 1833; he did so again in 1850; and he admitted, soon after the convention, that he "should be glad to see" Texas annexed, if it could be done without war. This failure of the Whigs to oppose the extension of slavery, together with their having made the tariff highly protective in 1842, cost them so many votes in New York and Michigan that they lost the election. Negligence and dissension at the North had enabled the South to set aside Van Buren in favour of Polk at the Democratic convention. The party was pledged to annex Texas; and Northern members were appeased by a crafty promise that all which was worth having in British America, west of the Rocky Mountains, should be acquired also. The declaration in the platform of 1840, that the government ought not "to foster one branch of industry to the detriment of others," was repeated in 1844, as often afterwards, but it was so cunningly explained away in Pennsylvania that this State voted for the President who signed the low-tariff bill of 1846. The election of 1844 strengthened the influence of the South. Texas was soon annexed by the same Congress which had refused to do so previously, and was admitted like Florida, as a slave State, in spite of remonstrances made by the legislatures of Massachusetts and Vermont, as well as by two-thirds of the Unitarian ministers. In March, 1846, Polk's army invaded Mexico; her soldiers resisted; the Democrats in Congress voted that she had begun the war, which lasted for the next eighteen months; and the Whigs assented reluctantly. Most of the volunteers were Southerners, and there was much opposition at the North to warfare for the extension of slavery. The indignation was increased by the publication of Whittier's pathetic poem, _The Angels of Buena Vista_, as well as of that series of powerful satires, Lowell's _Biglow Papers_, The greatest achievement of literary genius thus far in America was the creation of _Birdofre-dom Sawin_; and no book except Mrs. Stowe's famous novel did so much for emancipation. A foremost place among abolitionists was taken by Parker in 1845, when he began to preach in Boston. His first sermon against the war with Mexico was delivered the same month as the publication of the first of the _Biglow Papers_, June, 1846.