61 years ago - Johnny Chambers is born.
45 years ago - 16-year-old Johnny begins working as a photojournalist.
41 years ago - 20-year-old Johnny discovers his speed formula during his travels.
38 years ago - 23-year-old Johnny begins using his speed powers as Johnny Quick, and helps form the All-Star Squadron
30 years ago - 31-year-old Johnny stops a heist, in which Roscoe Dillon is caught in a spatial backlash of speedforce energy, and gains an uneven connection to the speed force. He becomes The Top, experimenting with new ways to weild the Speed Force in a fight.
24 years ago - 37-year-old Johnny & Libby Lawrence have their daughter Jesse Chambers, and both retire.
20 years ago - 41-year-old Johnny develops his theory that the formula is a mantra to unlock his own hidden genetic potential & founds Quickstart Enterprises. He and Libby get divorced after she has an affair with John Law.
The fact that DC has more than one speedster isn't actually as weird as it might seem. Characters that can run super-humanly fast are remarkably prolific; even before the Flash started spinning off into tons of legacies, DC had several of their own, largely thanks to their tenancy to buy up other companies characters. Johnny was part of More Fun Comics, but was an early transition into DC proper.
Much of the fun of Johnny Chambers was crafted after the fact. The All-Star Squadron was mostly built as a retroactive rewrite to bring various World War II era characters into DC's past, and Johnny himself didn't really come to prominence until the invention of his daughter Jesse, and his featured role in the elseworlds story Golden Age. As Jesse was featured in Wally West's adventures, we learned more about what sort of father and what sort of man he was.
He's become a character best remembered for his profound ideas about his own powers, and for his multifaceted relationship with his wife and daughter. The complex nature of those relationships is likely due to the roles he and Libby played in Golden Age, and the result is a character custom built to be a founding father of of the modern superhero age.