Missouri is a state located on the midwestern region of the United States of America.
Captain America Comic
Gary Hendricks, a young fan of the war hero Captain America, received a copy of a comic book edited to help boost morale during World War II, that told an action-packed story about his favorite Star-Spangled Hero.
Hendricks avidly read the story where Captain America stopped a group of military traitors from stealing a newly-created bulletproof Electro Suit. Captain America, triumphant, swore that he would ever be vigilant and protective of the nation's freedom.
Hendricks finished reading the comic, and entered his home to have dinner. The mailman left Hendrick's mail near the comic, as he knew that he would be back to retrieve it.
In the late 1970s and early 1980s, Ego took on a human form and visited Missouri on Earth a total of 3 times, in order to plant one of his seeds to include Earth in his "expansion" plan. During this period he fell in love with Meredith Quill and impregnated her. However, because of the fact that his planet would perish if he leaves it too long, and because he felt Quill was becoming a major distraction to his plan, he planted a tumor in the back of her head and permanently left. Meredith would eventually give birth to Peter Quill following this.
In 1988, Peter Quill went to the hospital where his mother, Meredith had been admitted suffering from terminal cancer caused by the tumor Ego planted in the back of her head. He sat in the waiting room of the hospital, while his grandfather and the rest of his family spent their last moments with Meredith.
Peter listened to his "Awesome Mix" tape on his Walkman until his grandfather came over to him, telling him that his mother wanted to speak with him. He took Peter's headphones off of his head and put the Walkman inside his backpack.
Peter entered the room, where Meredith was lying sick in a bed. Meredith noticed that Peter's eye was bruised and asked him why had he been fighting with other boys. Peter shrugged his shoulders, but then admitted that he confronted the other boys for killing an innocent frog.
Meredith compared Peter to his father, whom she described as an angel composed of pure light. Meredith's eyes closed for a moment, so her father called her out loud to avoid that she lost consciousness, and reminded her that she had a present for Peter. Meredith handed his son the gift and a letter, and his grandfather put them in the backpack.
Meredith told Peter to open the letter and the gift when she was gone, and Peter started to cry. Meredith promised his son that his grandfather would take care of him until his father came back to retrieve him, and asked Peter to take her hand.
Peter looked away crying, and despite his grandfather prompted him to take Meredith's hand, Meredith's heart stopped before he took her hand. Peter called to his mother, and as Doctor Fitzgibbon rushed into the room, Peter's grandfather carried Peter out and asked him to stay outside.
Peter watched how his grandfather walked back into the room, and then he ran outside the hospital, falling to his knees as he continued crying. Suddenly a spaceship appeared on the sky above Quill, and its occupants abducted him, taking him out of Earth upon his father's request.
Investigation of the Mandarin Attacks
In 2012 Springfield was the location of an unusual thermogenic occurance, in which the thermogenic signature rose to 870 degrees Celsius.
Tony Stark started investigating the Mandarin, in order to enact revenge for the explosion that almost killed Happy Hogan. As usual, the explosive device was not found, but the heat from the blast was particularly high, more than 3000 degrees Celsius.
Stark studied the different thermogenic occurances to study other cases based on the particular temperature of the explosion, discarding the thermogenic signature at Springfield for not being as high as that of the explosion.
In 2014, as the Battle on Ego's Planet took place in a separate part of the universe, the seed previously planted by Ego erupted into a blue blob and began to devour Missouri, with the intention of eventually eating up all of Earth. Many civilians, despite attempts to flee, were swallowed up and killed. Eventually, thanks to the efforts of Peter Quill and the Guardians of the Galaxy from Ego's planet, the seed stopped devouring the area and eventually perished along with Ego.