From the Publisher:
What would have happened if history had been different - if the major events that shaped our times had occurred in a different way... or not at all?

In this intriguing volume, fifteen of science fiction's most imaginative minds alter the past to create a present of startling possibilities. From a Confederacy that won the Civil War to a Europe converted to Viking paganism, from Albert Einstein as a frustrated violin teacher to a Christian Ghengis Khan, these bold excursions in time depict bizarre new worlds - oddly familiar, yet disturbingly different.

Contents:

• A Sleep and a Forgetting by Robert Silverberg
• The Old Man and C by Sheila Finch
• The Last Article by Harry Turtledove
• Mules in Horses' Harness by Michael Cassutt
• Lenin in Odessa by George Zebrowski
• Abe Lincoln in McDonald's by James Morrow
• Another Goddamned Showboat by Barry N. Malzberg
• Loose Cannon by Susan Shwartz
• A Letter from the Pope by Harry Harrison and Tom Shippey
• Roncesvalles by Judith Tarr
• His Powder'd Wig, His Crown of Thornes by Marc Laidlaw
• Departures by Harry Turtledove
• Instability by Rudy Rucker and Paul Di Filippo
• No Spot of Ground by Walter Jon Williams

Edited by Gregory Benford and Martin H. Greenberg.