1752 - Scott Free is born on New Genesis the son of the All-Father. he is traded to Apokolips to seal their non-aggression pact. he is raised in Granny Goodness's Terror Orphanages, where he meets Big Barda.
9 years ago - Scott escapes Apokolips to Earth with the help of Big Barda and is taken in by Thaddeus Brown, a circus escape artist. When Brown is murdered, Scott takes on his stage name Mister Miracle to solve the crime.
6 years ago - the Female Furies track Scott to Earth where he continually escapes them. Big Barda turns to his side to defeat the Furies. They are married on New Genesis by All-Father, and retire to Earth.
4 years ago - Scott & Big Barda are attacked by a Parademon wave. They return to Apokolips to win their freedom in combat.
1 year ago - Scott helps Big Barda & Watchtower fight Maggeddon. He joins the new Justice League with her.
Mister Miracle might be the most Kirby-esque character to make it into the DC mainstream continuity. There are other New Gods that have joined the Justice League, most notably his wife Barda, Orion, and even lesser-known characters like Lightray, but none have maintained a steady, humanizing presence on Earth, building a life for themselves.
We've deliberately chosen not to attempt to build a chronology of the New Gods. They're a singular creation, existing within their own notion of time. Instead, we're simply telling these character's stories. We've slimmed down the number of New Gods-related characters that wind up interacting with the Justice League in order to make sure that the main ones stand out.
For Scott's part, I believe the absolute best place for him to be is right where he is; alongside his awesome, awesome wife.