Peter Quill's Grandfather was married and had one son and one daughter named Meredith Quill. In 1980, Meredith met Ego, an extraterrestrial Celestial entity and gave birth to his grandson Peter Quill.
In 1988, he was present at the hospital by Meredith's side as she was dying of cancer. He left Meredith's side to bring Peter into the room so Meredith could say her final goodbye. He then placed her final gift to Peter in his backpack. When Meredith flat-lined, he took Peter from the room before rushing back to Meredith's side.
Running from the Expansion
Years later in 2014, Quill witnesses the Expansion taking place, consumining a large part of Missouri. He attempts to flee by driving away from it. As the Expansion overtakes his car and starts absorbing it, he looks around in horror and then confusion as it stops and subsides.