King became vice president when Franklin Pierce became president, on March 4, 1853. King was not, however, in Washington, DC, for the occasion, having gone to Cuba a few months earlier in the vain hope that the warmer climate would help his tuberculosis. King received a special dispensation from Congress to be inaugurated vice president while in Cuba, and thus took the oath of office on March 24, 1853, which was administered by the US Consul at Havana, William L. Sharkey. Deathly ill, Vice President King wanted to die in Alabama, so in April he returned, living just long enough to make it home. He died on April 18, 1853.
King wasn’t the shortest-serving vice president, though the two who served less time – John Tyler and Andrew Johnson – became president instead of dying in office. He’s also a footnote for the speculation surrounding him and James Buchanan, who became president about four years after King died. That they were close, there is no doubt. Just how close will never really be known, however, though it’s all too easy to project latter-day sexual notions on the past that the past isn’t going to bother to confirm or deny.