Bring the Jubilee
Trapped in 1877, a historian writes an account of an alternate history of America in which the South won the Civil War. Living in this alternate timeline, he was determined to change events at Gettysburg. When he's offered the chance to return to that fateful turning point his actions change history as he knows it, leaving him in an all too familiar past.
The United States never recovered from The War for Southern Independence. While the neighboring Confederacy enjoyed the prosperity of the victor, the U.S. struggled through poverty, violence, and a nationwide depression.
The Industrial Revolution never occurred here, and so, well into the 1950s, the nation remained one of horse-drawn wagons, gaslight, highwaymen, and secret armies. This was home for Hodgins McCormick Backmaker, whose sole desire was the pursuit of knowledge. This, he felt, would spirit him away from the squalor and violence.
Disastrously, Hodgins became embroiled in the clandestine schemes of the outlaw Grand Army, from which he fled in search of a haven. But he was to discover that no place could fully protect him from the world and its dangerous realities….
#42 in the Millennium SF Masterworks series, a library of the finest science fiction ever written.