Trench warfare began in the American Civil War
While commonly associated with the Western Front in the First World War, trench-style defensive warfare first appeared in the American Civil War .
In the course of the Civil War, both the Union and the Confederacy learned the value of field fortifications. Both sides suffered tens of thousands of casualties learning the hard way how unassailable these fortifications were. Many generals were not quite convinced that these fortifications were basically invincible and continued to try different tactical maneuvers to break through them, with no success.
- Gwynne, S. C. Hymns of the Republic: The Story of The Final Year of The American Civil War. New York: Scribner, 2019.