Turtledove, Harry. "Lee at the Alamo"
Divergence: 1861 CE
What if: Robert E. Lee was in command of the Department of Texas when Texas voted to secede from the Union.
Summary: With Virginia as yet still in the Union, Lee does his duty as a U.S. Army officer.
Published: Posted on Tor.com, Sep. 7, 2011.
Awards: Finalist: 2011 Sidewise Award for best short-form alternate history.
Web link: Tor.com