I was just reading the Wikipedia entry for Confederate States of America President Jefferson Davis and it includes the fascinating factoid that, despite being elected to numerous offices, he never completed a whole term in any of them.
The year 1844 saw Davis's first political success, as he was elected to the United States House of Representatives, taking office on March 4 of the following year. ...The year 1846 saw the beginning of the Mexican-American War. He resigned his House seat in June, and raised a volunteer regiment, the Mississippi Rifles, becoming its colonel. On July 21 they sailed from New Orleans for the Texas coast. ...
Because of his war service, the governor of Mississippi appointed Davis to fill out the Senate term of the late Jesse Speight. He took his seat 5 December 1847 and was elected to serve the remainder of his term in January 1848. When his term expired, he was elected to the same seat (by the Mississippi legislature, as the Constitution mandated at the time). ...
He had not served a year when he resigned (in September 1851) to run for the governorship of Mississippi on the issue of the Compromise of 1850, which Davis opposed. This election bid was unsuccessful, as he was defeated by Henry Stuart Foote by 999 votes. ...
Pierce won the [1852 presidential] election and made Davis his Secretary of War. ... Davis's term was to end with Pierce's, so he ran successfully for the Senate, and re-entered it on March 4, 1857. ...
Though an opponent of secession in principle, Davis upheld it in practice on January 10, 1861. On January 21, 1861, he announced the secession of Mississippi, delivered a farewell address, and resigned from the Senate. ...
Davis was elected to a six-year term as president of the Confederacy on November 6, 1861. ...
On April 3, 1865, with Union troops under Ulysses S. Grant poised to capture Richmond, Davis escaped for Danville, Virginia, together with the Confederate cabinet, leaving on the Richmond and Danville Railroad. He issued his last official proclamation as President of the Confederacy then fled south to Greensboro, North Carolina. On May 10, he was captured at Irwinville, Georgia.