The party was also torn on the issue of slavery. Most in the party wanted to prevent slavery from becoming the dominating issue in the election. However, the Whigs were split on the issue of the Compromise of 1850, proposed and designed by Whig Senator Henry Clay of Kentucky. President Zachary Taylor, a Southern Whig, had tried to avoid the issue altogether by proposing that California and New Mexico be admitted as free states immediately. After Taylor's death in July 1850, Fillmore, a moderate Whig, had supported Clay's compromise and was instrumental as president in its passage. Northern Whigs, led by William Henry Seward of New York, (former Governor and Senator), adamantly opposed the compromise because it did not apply the Wilmot Proviso (which banned slavery in any federal territory acquired from Mexico after the Mexican-American War) to the western territories.