The city was incorporated in 1834. It is possible it is located on the border of the Great Lakes, as the primary imagery in the city seal in a lighthouse.
Midway City was founded in 1834.
Battle of Midway City
Attack on the city
In 2016, while sleeping in Midway City, June Moone transformed into Enchantress against her will. Right after, she left to find the vial containing her brother Incubus, who she unleashed into Gerard Davis, a man in the subway. Together, Enchantress and Incubus destroyed parts of Midway City and created a mystical super weapon referred to as "the ring". When the time came, Incubus attacked the Midway City subway, absorbing many people to restore his true form and destroying trains. The efforts of the US military and local police to "contain" him failed dramatically, the first responders being wiped out by Incubus' tentacles.
Calling on Task Force X
Waller then called on Task Force X to extract a valuable person from Midway City. The team, led by Rick Flag, contained Deadshot, Harley Quinn, Captain Boomerang, El Diablo, Killer Croc, Katana, and Slipknot. Later, Waller sent June Moone and Rick Flag to destroy Incubus, but the attempt turned into an opportunity for Enchantress to make an escape and join her brother instead. Although without her heart, she was unable to bring the full extent of her powers to bear, and was saved from an apparent death under Waller's hands and restored to her more "healthy" form by her brother sharing his power with her. She then used her power to create both her army and her super weapon. While Incubus continued to wreak havoc in the city and destroy the military's attacks against them, he also contributed to the super weapon by lifting the wreckage of buildings and destroyed military equipment to the "ring" now hovering above Midway City. The military was then forced to evacuate and call up the rest of the Suicide Squad against this new threat.
Fighting in the streets
Together, Task Force X fought Enchantress' Eyes of the Adversary in the streets who specifically targeted Rick Flags due to his relationship with June Moone, swarming them. Slipknot was by his nano bomb, as he was attempting to leave instead of fight with the rest of the Squad after being told by Captain Boomerang that it was just a hoax. Together, the remaining members of Task Force X won the battle against Enchantress' minions, and they continued their mission.
Death of Enchantress and Incubus
In a final battle against Enchantress, the remainder of Flags' men and Killer Croc went underwater to plant a bomb beneath Incubus, while the others entered and fought the Enchantress and her forces. The usually placatory El Diablo amplified his powers, increasing his size into a large flaming avatar and managing to subdue the Incubus, sacrificing himself to detonate the bomb underneath, resulting in an explosion that destroys both El Diablo and the Incubus as well as the machine, ending the Enchantress’ hex. Enchantress was then killed, and June Moone remained alive and escaped, reuniting with Flag.