In its day, Buster Keaton's 1926 comedy The General was a huge flop, but it has since gone on to become retroactively seen as a classic. Some would argue that it is one of Keaton's best films, and it has certainly become one of his best known to modern audiences. The film was loosely inspired by the Great Locomotive Chase of 1862, an incident during the American Civil War in which Union forces attempted to hijack a train and take it northward while sabotaging the tracks to cut off supply routes for the Confederate Army, only to be pursued and eventually captured.
Keaton's film is likely not an accurate recreation of what happened historically. Instead, he uses the story as a means to bring out his iconic brand of slapstick humor. It was not an easy movie to film either. In order to film the moving trains, cameras had to be placed on parallel tracks and move alongside the various locomotives used throughout the film. That said, Keaton does have some things to say about the American Civil War amidst the various stunts, accidents, and misunderstands of his bumbling protagonist Johnny Clay.
The General makes the clear and deliberate choice of avoiding any reference to the politics of the American Civil War. The film is shown from the perspective of the Confederacy, but for the most part the details of why anyone is fighting are left out. All that is established is that there are two factions: the North and the South, and both hate each other. Instead of establishing any background on the war, Keaton begins by placing the viewer in an unidentified southern town where he first introduces Clay as an everyman protagonist.
We learn that he is a fairly ordinary person who has "two loves" in his life, his engine (the titular General) and Annabelle Lee (Marion Mack) to whom he is presumably engaged. We see that Keaton is living what for the time may have been a fairly normal life, with him going to visit Annabelle's house and knocking on her door, unaware that she is standing right behind him. This brief but notable focus on everyday life is extremely important, because not long after we learn that the Civil War has begun. No mention is made of the politics or why the war is happening.
In fact, we only find out by word of mouth, one man passing the story on to our heroes (presumably after reading about it in a newspaper). Instead of focusing directly on the war itself, Keaton instead opts to place the emphasis on how it affects the people of this particular town, especially Johnny Clay and Annabelle Lee. Both are treated throughout the movie as civilians caught in the crossfire of a war they barely understand (only at the end does Keaton become a soldier, and even then not a very good one).
This lack of understanding comes to the forefront early on when we see the mentality that comes with the outbreak of the war. The people in town clearly have never served in the military before, and a sentiment quickly develops that the men have to enlist and fight for the south. Annabelle's father and brother immediately agree to this, and quickly press Clay into following. But Clay becomes so excited to enlist he actively cuts in line and almost walks right past the recruiting booth by accident. When they refuse to enlist him (under the assumption that Clay would be more useful as an engineer than as a soldier), he makes multiple repeated efforts which include a "disguise" which involves tipping his hat sideways and stealing other people's recruitment slips.
After all that, Clay fails to enlist and even though he had no say in the matter, finds his life shattered when he is immediately branded a coward. Annabelle's father later manages to twist the facts to make it sound like Clay was too scared to enlist (and describes being reluctant to go to war as a "disgrace"). This is unfortunately something that tends to happen when people who have never seen war up close get too patriotic. The same thing happened years later during World War I (and could easily have been witnessed by Keaton himself), another era in which men were peer pressured into going to war and faced with public shaming if they failed to do so.
This one action seemingly destroys the ideal life Clay had shown in the movie's opening. Annabelle, having been told by her father that Clay is a coward, refuses to speak to him, likely ending their relationship for now. The war has only just started and already Clay is beginning to feel its effects without being anywhere near any of the battlefields. His feelings are visually conveyed in one of the film's most iconic shots, in which Buster Keaton sits on the wheels of a steam locomotive while an engineer fails to notice. Keaton gets moved up and down in one direction, through a tunnel, showing the lack of control he has over what is going on.
As the movie progresses to some time later, we see that the Civil War has started to have a much greater effect on the South. Annabelle's brother appears to have been wounded, and his arm is in a sling. Her father has apparently faced even worse injuries, enough that she is taking a train to go see him. At this point, she is really more or less an ordinary person just trying to cope with a difficult situation, another victim of the war who ends up getting mixed up further by being in the wrong place at the wrong time. One small act of inconvenient timing leads to Annabelle being abducted by Union Soldiers and dragged into northern territory. Clay is not even aware of this happening, all he understands is that his train has been stolen and he needs to get it back.
Clay initially takes on this role purely as an engineer. The Union soldiers manage to sabotage the telegraph lines, so the only way to call for backup is to drive to the nearest outpost and alert the soldiers there. Even then, in all the commotion, Clay accidentally forgets to lock the transport car to his engine and ends up pursing the Union on his own. He does this entirely by accident and does not realize what has been going on until it is too late to turn back. Here, Clay finds himself alone, stuck in the middle of a war and not really on either side. All he is concerned about is reclaiming The General, and he lacks any real interest in what is actually going on.
Unfortunately, he also has to adapt to the difficult circumstances brought out by the Union soldiers, who routinely sabotage the tracks and pull a variety of tricks to try and get ahead. Clay has to resort to improvisation, relying only on whatever he can find, and even this is not always enough. We see that he quickly starts to run low on firewood and breaks his ax in the process. He does manage to find a canon, but it turns out not to be very effective. The first shot only launches a ball into his cab, the second nearly takes out his train. The only reason he is even able to keep the Union Army running is because they mistakenly assume that he is driving a train full of Confederate soldiers.
Clay's status as a civillian comes up later on, when in his pursuit, he witnesses a skirmish between the Union and Confederate armies. The film mixes various shots of soldiers on both sides along with Clay struggling to keep his head down while moving forward. In all the chaos, nobody seems to notice him, but he is able to witness the destruction that occurred in the war, if very briefly and from a (relatively) safe vantage point. All Clay wanted was his engine back, but now he is stuck in the middle of a war which he has no control over.
Eventually, Clay is finally forced to stop, but by this point there is little he can do. He has unwittingly followed the soldiers into Union territory, and now finds himself lost and alone. It is entirely by accident that Keaton manages to obtain information. He begins the sequence stopping at the first building he sees, where he tries to quickly obtain food. It is only coincidence that he ends up accidentally wandering into a military conference. The only reason he even learns Annabelle has been taken is because he manages to briefly glimpse her through a rip in the tablecloth, but during the conversation, he is mainly trying to avoid being caught.
Clay does manage to rescue Annabelle, but not out of any sense of patriotic duty. He does it because, as was established in the beginning of the film, he cares for her. While Clay did overhear information that would be useful to the south, his main goal is really to get out of Union Territory alive, and to do so he has to make a large gamble. The only viable way of quickly getting out is to sneak into a military trainyard and steal back the General, which is a long shot at best. One mistake could mean the difference between life and death in his case.
When Clay finally returns, he is almost shot after a sentry mistakes him for a Union soldier, and quickly has to change into a southern uniform. When he brings information to the people at home, it ends up being chaotic once again. Clay is quickly lost amidst the chaos of the battle. First he is just trying to focus on not getting run over in the street as cavalry charge into position. When he actually enters, his only weapon is a sword that fails to stay together, and spends much of it unsure of what to do. Every time he draws his sword, the blade falls off, making it largely useless except for one accidental victory (it manages to take out an enemy sniper).
Clay tries to co-ordinate some of the soldiers, but this proves ineffective as he keeps watching them die. In the end, it is nothing more than luck that gets him through his mess, and his accidental heroics end up getting him a promotion to lieutenant. Still, this hardly makes Clay's life any easier. Although he is able to win Annabelle back, he also finds himself struggling with new responsibilities and problems he was never prepared to handle. This is humorously shown by the film's final moments, when Clay and Annabelle try to have a private moment on the wheels of an engine (contrasting the earlier scene where Clay was alone in the same position) only to keep getting interrupted by the presence of a large garrison of soldiers.
In the end, Clay's life will never be the same. Even if things have ultimately worked out, he has been affected by the war just as everyone else has or will be, and he will continue to feel its effects (this is especially likely when one considers that the South lost the war, which could easily have a negative impact on Clay's personal life). The General is really a story about how ordinary people are affected when they are drawn into a war they do not understand, and how it can permanently change their lives.