During the war the Wilmot Proviso was the subject of frequent debate in Congress and of continuous debate throughout the country until the treaty with Mexico was signed in 1848. A vast territory had been acquired as a result of the war, and no decision had been reached as to whether it should remain free or be opened to settlement by slave-owners. Another presidential election was at hand. For fully ten years there had been ever-increasing excitement over the question of the limitation or the extension of slavery. This had clearly become the topic of supreme interest throughout the country, and yet the two leading parties avoided the issue. Their own membership was divided. Northern Democrats, many of them, were decidedly opposed to slavery extension. Southern Whigs with equal intensity favored the extension of slavery into the new territory. The platforms of the two parties were silent on the subject. The Whigs nominated Taylor, a Southern general who had never voted their party ticket, but they made no formal declaration of principles. The Democrats repeated with colorless additions their platforms of 1840 anti 1844 and sought to win the election with a Northern man, Lewis Cass of Michigan, as candidate. There was, therefore, a clear field for a party having fully defined views to express on a topic of commanding interest. The cleavage in the Democratic party already begun by the debate over the Wilmot Proviso was farther promoted by a factional division of New York Democrats. Martin Van Buren became the leader of the liberal faction, the "Barnburners," who nominated him for President at a convention at Utica. The spirit of independence now seized disaffected Whigs and Democrats everywhere in the North and Northwest. Men of anti-slavery proclivities held nonpartizan meetings and conventions. The movement finally culminated in the famous Buffalo convention which gave birth to the Freesoil party. The delegates of all political persuasions united on the one principle of opposition to slavery. They adopted a ringing platform closing with the words: "Resolved, That we inscribe on our banner 'Free Soil, Free Speech, Free Labor, and Free Men,' and under it will fight on, and fight ever, until a triumphant victory shall reward our exertions." They accepted Van Buren as their candidate. The vote at the ensuing election was more than fourfold that given to Birney in 1844. The Van Buren supporters held the balance of power between Whigs and Democrats in twelve States. Taylor was elected by the vote of New York, which except for the division in the party would have gone to Cass. There was no longer any doubt of the fact that a political force had arisen which could no longer be ignored by the ruling parties. One of the parties must either support the new issue or give place to a party which would do so.