The Whig Party won two presidential elections in the 19th century before the onset of the Civil War. William Henry Harrison won in 1840 and Zachary Taylor won in 1848. However, looking at the brief administrations of the winning tickets, it is hard not to feel bad for those hard luck Whigs.
President Harrison won with John Tyler on the "Tippecanoe and Tyler too" campaign slogan. Alas, Harrison died a little more than a month into his administration. President Tyler became the second Whig president. However, he was so opposed to Whig policies that the Whigs officially kicked him out of the party in 1841! The Whig victory of 1840 was short and they got little out of it.
The 1848 election was slightly more kind to the Whigs. President Taylor lived almost a year and half before he died. President Fillmore became the fourth and last Whig president. While he remained a Whig, many in the Whig Party were not enamored with him. Taylor's entire Cabinet resigned on Fillmore in protest to his policies.
After winning two presidential elections, having four presidents, and holding the White House for eight years, the Whig Party had little to show for it. Historians point to the crisis over slavery, the growing north-south divide, and finally the Civil War for ending the Whig Party.
I wonder though if it was not hard luck of the Whig presidents that brought an end to the party. What if Harrison and Taylor had served a full terms? What if one or both had won second terms? Would strong Whig presidents have been able to solve the constitutional problems that lead to the Civil War? I wonder how different history would have been had the Whigs had some good luck in the White House.
Regardless, I wonder if the fate of Harrison and Taylor convinced other good candidates not to run for president as a Whig. The life expectancy of their winning presidential candidates was not too good...