My country has had a civil war, invasions by the french, by the spanish, more recently a revolution that threw a fascist government, followed by a very colourful period of internal squirmishes between anti-regime forces, but we settled those events and that was that: off to the history books.
What motivates so many people to re-enact battles from the American Civil War?
It sounds cruel. Re-enacting a war where so many died gruesome deaths.
It seems like you have two questions combined into one. First, is why do people do historic reenactment of wars? Second, why do Americans choose this war?
For the first answer, performing historic reenactment of wars isn’t solely an American thing. It is common for Europeans to reenact Napoleonic war battles. I’ve also seen cases of people dressing up as Roman soldiers in military camp. Beyond that, historical reenactment of various forms of veracity are common in different parts of the world as a type of cosplay. Wars end up being a popular thing to cosplay because there is narrative conflict; it is a real life story.
Why the American Civil War? It is a very significant war in American history, one of the three most important wars. Compared to World War II, it isn’t problematic to depiction both sides fighting; it is a lot more problematic for people to dress in Nazi, Imperial Japanese, or even fascist Italian uniforms. Compared to the American Revolution, the uniform matches more modern fashion, so it is easier to buy equipment to cosplay. Also, the equipment was mass produced, so it is easier to buy replica equipment, including firearms.