Back in 1776, two months after America got its first taste of freedom an English man turned to books of elder times to get revenge for a child he lost in the war. It took until August of the same year they got their independence for the first demon in many many years to be summoned.
The man however did not have the means to control the demon. The demon went on a rampage killing as many as possible and using those who lived to summon more demons. Soon the English man's whole village was run by demons when the first American settler snuck in to see what was going on. He returned home three days later missing a few limbs and some how teleported across an ocean in one night.
From that point on America began preparing for the demons incase they came over. Eventually they did in 1779. The American were prepared but, were almost completely destroyed. Yet, they some how won the battle but, from that point on American began human experimentation to protect themselves. This lead to the creation of Vampires, dragons, mutants and werewolves. It also lead to very few people being able to use different forms of magic, this number would expand heavily by the time our story takes place.
When the demons tried to invade again in 1781, they almost won once again but were defeated by the demons an again. When they retreated back to their tiny village, the demons decided to take over a bit more of England instead. England had to build a wall for protection half way through their way from 1781-82. In 1782 half of England belonged to the demons. Then the year later part of Ireland would be theirs as well. Once they got more land they began their experiments creating their own hybrids.
Eventually in 1795 the demons began making peace and retreating their boarders. They started to calm down and give land back for a reason to this day that no one knows. Yet, the demons soon had their own king and queens living in a tiny part of England. Then began return land to Ireland. The lands found peace and the demons had their own kingdom near England now. However American and the rest of the world seemed to hate them.
That is until the civil war in 1861 where the demons sided with the rebels. When they helped to win the war, well let's just say the world learned to love them. Demons began moving over into America and a few other snuck a few new creatures out. This lead to vampires going to Spain and creating their own empire. As for the werewolves they began fighting for rights in Canada where they made their own villages and protecting others.
As for the other experiments they began living actual lives. Traveling, marrying and having children to other experiments. Eventually they could marry humans in 1898. Then they could get normal jobs in 1900 that weren't going to result in their deaths. Many experiments began voicing their minds and rights. Everything seemed peaceful and more progressive.
That is until 1914 when world war 1 started. The Germans had mutated their own humans to help their allies that resulted in the first banshees being successfully made. They were the main weapons of death for the first war for the first year. While Germany's and its allies fought for power over the world, the forces on the other side fought together.
Yet, a year before the war ended, Austria caused the first rip. The first rip into another dimension. This resulted in a new super power joining them. They lost the battle but these peoples were then stuck in a dimension that they had no clue how to survive in. So the winners graciously gifted them land resulting in two new royal families joining the world.
These royal families were divided down the middle in World War Two. One joined the allies and one joined the Axis. From that point on the two hated each other. Especially after the war ended.
During world war 2 the first Alien was found by Italy. He was dissected and had his organ harvested to see its effects on humans. This would later come back to bite the whole earth in the behind two months after ww2 ended. Two months after the war ended, the aliens came to earth to avenge the king of the most powerful planet.
This battle lasted seven year and didn't end with earth winning. Instead the aliens won but, soared as many as they could. After earth submitted themselves to the aliens, they agreed to let them continue life the same as before but, would open their boarders to what ever the aliens wanted to do. Without a choice they agreed.
So earth became like a tourist spot for the whole galaxy. One where they were not permitted to leave but, were permitted to have normal lives. Or a least they were until 1991 when the Cold War ended. Or more like forcefully ended. America and Cuba had "fûcking bombs aimed at each other for no reason" as the queen of Jupiter worked at one point.
Oh she was so pissed that she had both ships destroyed and put her foot down saying if the people running the planet didn't stop going at each other throats the would be both killing their own citizens and starting a war with all of space. Then the humans were told that as long as they weren't a politician, they could leave the planet.
This lead to the world in the story where mythical creatures, magic users, humans and alien all exist at the same time. A lot of which live on earth for fun but, can leave when ever they wish.