Turtledove, Harry, and Bryce Zabel. Winter of Our Discontent: The Impeachment & Trial of John F. Kennedy
Divergence: 1963 CE
What if: John F. Kennedy was not killed in Dallas.
Summary: A history of the next three years.
Comments: Incomplete novel whose first thee chapters were posted as they were written on the authors' book blog. No updates were posted after May 2007, but in 2013, Zabel published Surrounded by Enemies: What If Kennedy Survived Dallas?, q.v., which is either the full novel or a related project.
Published: On the authors' book website, March through May 2007.
Web link: Winter of Our Discontent