I admit I was drawing blanks for what to post, so instead of Sunday, it comes later. But I’m taking inspiration from the USA holiday, Independence day, and how it can be used in fiction as a backstory element.
Reality: historical background
This won’t be specifically about the Declaration of Independence, but way more general topic. The colonial era had left many scars across the world, and thus breaking off from the colonial powers was seen as a major step forward not only for the USA (though they’re the ones who celebrate it the most). I’ve seen a meme calling July a “F*ck Britain” month, because of how many former British colonies declared their independence in July.
While a declaration of independence, in any form, is usually a reason for celebration, there are situations where a “merge” can be seen as an equally historical moment, though these aren’t usually celebrated as much. The idea that comes to my mind right now is the re-connection of East and West Germany after the fall of the Soviet Empire (though I have no idea if this is something that has any celebratory meaning). Likewise, I vaguely remember there were propositions to mark joining the European Union an important day (not a public holiday, though) in my country, though that didn’t pass.
Using an independence day in fiction may seem easier because of the real-world examples. Fantasy, as my genre of choice, tends to teal with varying degrees of not-so-benevolent ruling systems, often as the antagonists to overthrow. However, this leaves little for build-up of such an event, let alone to show it, because that’s usually the end of a story. It may be something to explore in a sequel, though, if the author decides to return to that universe, even (maybe more so) if the next story takes place a few generations later.
If a story shows the attempt to usurp a country, then such an event from the past may be a rallying moment for the defenders to rise up and form some resistance, so it’s also a possible plot element.
There may also be a reason to celebrate the formation of an alliance. In case of “unity” days, it probably won’t be a full-time merge but rather a looser alliance, but both options (and more) are possibilities to be explored. One of the main triggers may be creating an alliance to form up a resistance against a stronger foe that none of the participants would be to defeat alone.
Another option may be a “ceasefire day” – remembrance of a day that brought a war to its end and brought peace for the inhabitants. This will likely take a different form, such as some form of remembering the fallen of the war. The grim reminder may become a stronger element in such an event, to remind the future generations what cost was paid to achieve a ceasefire and, possibly, to remind what were the reasons (especially if petty) to start the conflict.
Depending on the occasion, the remembrance of such a day can be varied – from a full-scale celebration through memorials to the fallen to building statues. Of course, it may be a combination. The impact may also be different on various parts of the society – a remembrance day may hold more significance to soldiers, for example. Keep in mind to stay true to the setting – a culture that is depicted to not favor ornate celebrations should reflect that in these cases.
Of course, times change, and what may’ve once been a good result may not be seen the same. A potential plot element would be a separatist movement starting their grand scheme to break free on a day of unity they saw as something that had brought them less than they hoped.
Before I wrap this up, an example from my own project. The backstory I mention a bit in the first book, expand slightly in the second, and it’ll come to be a major plot element in the third, is that the elves were united after a drawn-out war. House Redshard, one of the initiators of the wars, eventually lost the war. They joined the united kingdom for the trade benefits it provided, but ever grumbled to not having a major role. These festering hatreds will be a plot element testing the strained unity in the third book, and are a potential plot element for a sequel story I have in nothing but concepts so far. The capital, built after the war, has a small statue to remember the end of the war. Likewise, I plan to explore that conflict in a prequel, which is (likewise) merely a concept for now.