Randisi, Robert J. "A Bad End"
Divergence: 1863 CE
What if: The Confederacy won at Gettysburg.
Summary: The actor Booth plots to assassinate the president.
Comments: The nature of the historical divergence is not made clear until the very end of the story and in an author's afterword.
Published: In Alternate Gettysburgs (eds. Brian M. Thomsen and Martin H. Greenberg), q.v.