In the 1848 presidential election, Lincoln supported war hero Zachary Taylor for the Whig nomination and for president in the general election. In abandoning Clay, Lincoln argued that Taylor was the only Whig that was electable. Lincoln attended the Whig National Convention in Philadelphia as a Taylor delegate. Following Taylor's successful nomination, Lincoln urged Taylor to run a campaign emphasizing his personal traits, while leaving the controversial issues to be resolved by Congress. While Congress was in session Lincoln spoke in favor of Taylor on the House floor, and when it adjourned in August, he remained in Washington to assist Whig Executive Committee of Congress in the campaign. In September Lincoln made campaign speeches in Boston and other New England locations. Remembering the election of 1844, Lincoln addressed potential Free Soil voters by saying that the Whigs were equally opposed to slavery and the only issue was how they could most effectively vote against the expansion of slavery. Lincoln argued that a vote for the Free Soil candidate, former President Martin Van Buren, would divide the antislavery vote and give the election to the Democratic candidate, Lewis Cass.

With Taylor's victory, the incoming administration, perhaps remembering Lincoln's criticism of Taylor during the Mexican–American War, offered Lincoln only the governorship of remote Oregon Territory. Acceptance would end his career in the fast-growing state of Illinois, so he declined, and returned to Springfield, Illinois, where he turned most of his energies to his law practice.