What is Millard Fillmore best known for?

It's not unreasonable to say that Millard Fillmore, 13th President of the United States, hasn't gone down in history as one of the White House's more notable occupants. The general consensus among historians is that he was (at best) a mediocre President who did little, if anything, to prevent the country from sliding towards civil war.
Whatever the justice of such assessments, Fillmore is best known for being the last President ever to represent the Whig Party. The Whigs were similar to the old Federalists, the party of John Adams and Alexander Hamilton. They stood for strong, centralized government and the development of a modern industrial economy. They also held to a staunchly literal interpretation of the Constitution—not least as a means of reigning in what they saw as the governmental excesses of the Democrats under Andrew Jackson.
Fillmore failed to secure the Whig Party's nomination for the 1852 Presidential election, thus effectively ending his political career. The Whigs were split from top to bottom over the vexed issue of the expansion of slavery. As a supporter of the notorious Fugitive Slave Act, Fillmore had antagonized Northern Whigs, who were now very much in the ascendency in the party. Seven years after Fillmore left office, the party dissolved completely, with some of its members joining with the recently-established Republican Party of Abraham Lincoln.