Johnny (Buster Keaton) won't be marching home, as he is not allowed to enlist. His girl Annabelle (Marion Mack) won't speak to him because of it. They don't realize he is needed an an engineer.
The Yankees steal his train and Johnny jumps into action, not knowing that Annabelle is captured and on the train.
The chase is both funny and exciting as a chase should be. The Yankees try all manner of tricks to get away, and Keaton stays after them bumbling along.
Soon, he is behind enemy lines still chasing. Soon, he is on foot and finds out the enemy plans and has to rescue Annabelle. The scene with the bear trap is pure magic.
The chase is now reversed as he tries to get back to Confederate lines before the Yankees catch him. Annabelle wasn't much help and provided some great comedic moments.
As expected, Johnny does, in fact, come marching home finally and is made a Lieutenant.