For Want of a Nail (novel)

For Want of a Nail is a 1965 alternate history novel by Robert Sobel. The title is taken from the proverb "For want of a nail, the shoe was lost; for want of a shoe, the horse was lost; for want of a horse, the rider was lost; for want of a rider, the battle was lost; for want of a battle, the kingdom was lost," illustrating the butterfly effect.

The novel presents a timeline in which the Confederate States of America won the American Civil War. The point of divergence (the "nail" in the proverb) is General Robert E. Lee choosing to invade Harrisburg, Pennsylvania, rather than Gettysburg. This results in a Confederate victory at the Battle of Gettysburg, leading to European powers recognizing the Confederacy and ultimately, a negotiated peace that grants the Confederacy its independence.

The book then explores the alternate history of North America through the 20th century. It details the social, political, and economic developments of both the United States and the Confederacy, highlighting the differences and similarities to the actual historical timeline. The Confederacy develops along different lines, maintaining a more agrarian economy for longer and experiencing a different trajectory in terms of race relations and industrialization. The United States, meanwhile, remains a major world power but is constantly impacted by the existence of its Southern neighbor.

Sobel's novel explores themes of historical contingency, the impact of individual choices on large-scale events, and the enduring legacy of the Civil War. It is written in a pseudo-historical style, resembling a textbook or historical analysis, which lends it an air of credibility and invites the reader to consider the "what ifs" of history.