Springfield began as a town that was created by a vampire and his thralls in the 1800s, during the American Expansion into the west. This vampire wanted to escape persecution from Americans, and created a place that was relatively hidden and secret. His magical cultivation and changing of the land brought a few creatures nearby and made the place a magical hotspot. The town survived in peace until atomic warfare at the end of World War 2 shattered the magical masquerade in an event known as Mythic Dawn, where the energy of the atomic bombs broke the magical threshold, and brought a variety of magical creatures from other realms. Having brought the magical and mundane world together, the world struggled to cope with the discovery of magical creatures and society, but with time, the world eventually got used to it and essentially merged with it in the 1960s (we operate on a similar timeline but things happened for different reasons, the hippy movement for example was the movement to embrace magic and the occult). Mundane tech still exists, but mages and creatures existed alongside it. But when the Mythic Dawn happened, the vampire’s rivals learned of his location, and went there with the new arrivals to settle the score. The vampire was killed in 1961, and in his place a powerful magic beast ruled. After the upheaval was over, Springfield became a small city in its own right over time, and by 2015, it had a sizeable population of 35,000.

Springfield is a pretty basic city. It’s got everything one would need. Grocery stores, general stores, pharmacies, insurance agencies, adventuring guilds, etc. It doesn’t have much of a nightlife but it’s there. Most of the economy is based on service and agriculture, though there is a little bit of light industry supported here through the creation of magical items. The population is rather diverse, with humans, vampires, werewolves, demons and a few other sentient monsters roaming around. While most non-humans exist as otherworldly creatures, they typically live in their own neighborhoods/enclaves. Below are the races of folk that exist here:
Humans
Elves
Orcs
Goblins
Lizardfolk
Mermaids
Centaurs
Demons
Vampires
Werewolves
Undead
Dragons
Medusas
A few other DnD Monsters
Most of these creatures live in relative harmony with their own subcultures of sorts, but thanks to the Mythic Dawn, they are all American Citizens regardless, and participate as working members of society. However, some of their subcultures and values sometimes clash with the American values most of the long-timers have, and it causes some issues, but otherwise, most people are able to get along and enjoy the quiet life together.

Springfield | A small city of 35,000. Set in the American Midwest, this small city is otherwise unremarkable save for the incredibly diverse populace that call this place home. Springfield is normally a quiet town forgotten by the public, but every now and then it might show up on the news for the odd event that might happen in the state.
Morval Castle | This was the original castle that once belonged the vampire lord that started the original settlement.
Madison Heights | A wealthy suburb.
River Rock Villa | A mansion where the current city leader lives.
Bristol Township | A farmer town.
Kistch Lumber Yard | Active lumber yard.
Fairview Gate | A strange portal to another dimension.
Missile Silo NV2 | Abandoned cold-war missile silo.
Abandoned Grain Factory | A large grain factory that went out of commission in the 90s.
Abandoned Mine Shaft | A magic crystal mineshaft abandoned in the 2000s from monster infestation.
Ardenbrook Cave | A calm cave covered by soft waterfalls.
Mudwater Cave | A shitty cave with muddy water constantly flooding it.
Jasperkeep Farm | An abandoned farm that used to be part of Morval Castle.
State Highway 20 | An active but lightly travelled state highway, with a large bridge that crosses Fairview river.
Silver Lake | Massive lake filled with fishies, mermaids and maybe Cthulhu.
Fairview River | River that runs from the North to the South with several tributaries. Clean and lovely river with lots of biodiversity.
Tall Tree Forest | An enchanted forest with some insanely tall Kashyyyk trees.
Clinton Mountain Range | Smaller mountains that mark the northern county line for Fairview.