Primary sources are rarely have complete accuracy as writers only have some information and rarely ever have the whole story. Writers are just individuals and they don’t know all the reasons for why other people do things.
When we acknoledge this—like the makers of docudrama and historical fiction do—we can create something which might actually be closer to the truth than any sincere authentic recreation simply because we will always learn new things about the past but it’s not possible to learn new things from a docudrama without creating new canon.
The source material telling the narrative of the "losers" is often lacking in quantity and quality compared to the "winning" side.
But that does not mean that it is forever obscured or that any narrative is completely lost to history. Not at all.
Often, a re-emergence or a discovery of a discredited, ignored, or unheard narrative can really give us a fuller picture of conflicts throughout history.
Additionally, the passage of time usually shifts the answer to this question: "who really won?"
In many ways “the events as they transpired” doesn’t really exist but for the sake of this paper I will pretend that it matters the most. If we are trying to come up with an exact retelling of the past then I would say one story about the past is just one point. With two stories we can create an infinite line between them and the truth will exist somewhere along that line. It might only occupy 1cm of space on that line, but with two stories I think we will start to see some truth appear. With three stories we can connect them with some geometry and the truth will exist within some amount of space between the constraints of those three points.
Many Allied wartime myths became 'history' in the years following World War II for example. But over time those interested in events are less those involved and needing to interpret them, and more those interested in reconstructing events, motivations and patterns. History then tends to be somewhat freed of prejudices.
Each country publishes a history and indoctrinates its citizens. For the past 23 years I believed that it was the US which stopped WWII but it was actually a lot more complecated than that. When I was taught in school was that the US was central to stopping the war but that isn’t very true. Sure, we had some good fights and we did make a difference but I never was taught about the Red Army. The casualties to the US and Europe would have been much worse without the sacrifice of 34,401,807 russians who fought Hitler.
…for every single American soldier killed fighting the Germans, 80 Soviet soldiers died doing the same.
Sure their interests might not have been noble as US interests but its hard to know how noble US interests were when we ignored it for so long until Pearl Harbor.
…the values and norms we deal with today interpret history. History is in the eye of the beholder.
This also means that we have to be aware of modern biases changing how we view the past, just because we think it's inconceivable to own another person today, the last person who was owned as a slave in America died in ~1971.
primary sources directly name slavery and these sources have been written by many people including the vice president of the confederacy (facts back this reasoning up)
a few years after the end of the war southern's start using the state's right argument and that it had little to do with slavery (which isn't true)
The American Civil War was won by the North but there are arguments that the south "won the reconstruction" because the southern planter class hung on to power.
Being a winner in the sense of war doesn't mean you can rewrite history but being in power and keeping power means you can. Today this has changed as more and more historians can look at sources to confirm/disprove interpretations of events but their bias can still be noticeable. Historians don't write that slavery was okay because any body who argued that would be shunned today. This makes using primary sources all the more important.