What former U.S. Vice President would later become Secretary of War for the Confederate States of America?

We did it yesterday, so let's keep the streak alive: another Civil War question, this one from our Pocket Trivia: U.S. Presidents game.  What former U.S. Vice President would later become Secretary of War for the Confederate States of America?  Was it James Polk, John Breckenridge, John Calhoun or John Tyler?

This one always interested me - it's amazing to think that a former Vice President of the United States could wind up becoming one of the highest ranking officials in the Confederacy?

Alright - not John Tyler.  Tyler was Vice President to William Henry Harrison and became President when Harrison died.  When war broke out, Tyler tried to stop it via a compromise, but to no avail.  Instead, Tyler was elected to serve as a Congressman in the Confederate Congress (!!!!), but died before he could serve.  Harrison became the only President whose death was not mourned in Washington.

Not John Calhoun.  Calhoun, a Senator and one-time Vice President, was an advocate for states rights and the rights of slaveholders, but died ten years before the Civil War.

Not James Polk either.  Polk was a Congressman, Speaker of the House and U.S. President, but never V.P. Polk died 103 days after he left the Presidency in 1849.

The correct answer is John Breckenridge.  Breckenridge was something of a boy wonder and elected Vice President at age 35 - the youngest V.P. in history.  He ran for President in 1860 and came in third, winning only border states, having been nominated by the southern wing of the Democratic party.  He was expelled from the U.S. Senate in 1861 for supporting the South and eventually served as a successful general.  Named Secretary of War during 1865, the final days of the confederacy, Breckenridge helped to oversee an end to the Civil War and negotiate an honorable surrender with Union forces.  Breckenridge fled the country and only reentered in 1869 after having been granted amnesty.