Tiberius Kirk is a farmer in Iowa, around the time of the founding of the Federation. He was born at the time of a local fad of naming children after well-known ancients (there was an "uncle joke" in an episode of Welcome Back, Kotter that did this, involving a tailor named Euripides Feldman; the punchline was "Euripides?!" "Yeah! You menda dese?") (Speculation, but I recall something establishing a grandfather named Tiberius)
Tiberius has a son, George Samuel Kirk. George isn't interested in taking over the family farm; he worships Jonathan Archer, and wants to join Starfleet. He also worships the literal "girl next door" (even if "next door" is over a kilometer away), a young woman named Winona. Winona is a born farmer, and a born agronomist. The two marry while he's a cadet at Starfleet Academy San Francisco, and she's a University student (picking up various degrees from Iowa State, University of Iowa, Cal Poly SLO, and UC Davis); when their parents retire, she combines the two adjacent farms, farming (in the old measurements) some thirty quarter-sections. They have a son, George Samuel "Sam" Kirk, Jr. (Still speculation, but Winona is established as running the farm)
George Sr. takes a lot of ground and near-space assignments, wanting to be close to home for Winona and Sam, and at some point, he's mentored by a young officer named Robert April. Eventually, Starfleet gives him a deep space assignment, though, basically giving him a choice between 14 months on a science vessel, the USS Kelvin, or resigning his commission with an honorable discharge. They also encourage him to take Winona along as a civilian consultant. James T. Kirk is conceived some 4 months into the mission, and is born right about the time the Kelvin starts to head for home. (Speculation and the Kelvin scenes of ST09)
We all know what happens in the Abramsverse: George Kirk sacrifices his life to allow the crew of the Kelvin to escape, and in the wake of an attack by an apparently Romulan vessel of immense size and power, the Constitution Class plans are scuttled, in favor of a bigger, beefier, more heavily armed design, and the new ships are assembled in an Iowa cornfield, instead of in orbit, to better hide them from Romulan spies. And of course, James T. Kirk grows up without a father to rein in his juvenile delinquent tendencies, and resenting a stepfather who apparently cares more about his antique hydrocarbon-fueled vehicle collection than about his stepson. (ST09, and a bit of speculation about who is angry about the car)
But this isn't about the Abramsverse. In the Prime Universe, everybody aboard the Kelvin returns home, and George Kirk takes some much-needed leave before returning to ground and near-space assignments. And meanwhile, Robert April gets introduced to the Constitution Class plans, the first capital ships to be built truly under the UFP banner, and informed that he is to be the first captain of the first Constitution class ship.
(L7P, and the situation at the beginning of FF)
The first ship to have its keel laid is, of course, the Constitution. But production problems and technology changes result in a second, unnamed ship pulling ahead. Then Starfleet Command gets wind that a vessel, the Rosenberg, has been disabled by, and stranded in, an ion storm, with no hope of rescue . . . unless a Constitution class ship can be rushed out of the shipyard. (FF)
George has become Chief of Security at Starbase 2, with his protege, Francis Drake Reed (proudly, fiercely, from the West Indies, but possibly also a descendant of Malcolm Reed), from whom he'd picked up the nickname "Geordie." April has him shanghaied for the rescue mission. Which immediately goes awry, thanks to the machinations of a Romulan deep-cover agent. They eventually manage to escape (picking up a high-ranking Romulan defector in the process) and complete the rescue, but because the Federation was not ready to know that the Romulans originated as a Vulcan offshoot, everybody is sworn to secrecy, and that aspect of the mission is classified. At "Geordie" Kirk's suggestion, the new ship is named Enterprise, and it is completed and launched. (FF)
"Geordie" Kirk returns to near-space assignments. Winona, Sam, and Jimmy visit Tarsus IV on their way to a rendezvous with Dad. (Is there some other bit of TrekLit that establishes Winona as being there to help deal with the famine?) takes Jimmy along on what was expected to be a working vacation: a trip to Tarsus IV, to deal with a massive crop failure. Jimmy ends up witnessing the massacre, and saving the life of a young orphan, Kevin Thomas Riley, and ends up permanently scarred, and severely disillusioned about space. (My recollections of the flashback in A Flag Full of Stars)
Some time later, he begins running with a youth gang, and they run away from home, with the intention of signing aboard an oceangoing freighter. Geordie catches them, and arranges with April to take his son along on a "milk run" mission aboard the Enterprise. That, of course, turns into another monument to Murphy's Law, but James T. Kirk is no longer a juvenile delinquent. (BD)
April never commands a 5-year mission; he'd grown to realize that he was too much of an idealist. Pike commands several. On his first, he gets stuck in the Kalar Wars on Rigel VII, and then gets captured by the Talosians; his second is, of course, chronicled in SNW. (end of FF; "The Cage," and SNW season 1)
Oh, yes, and when Kirk finally gets the Enterprise, his first assignment is a milk-run, that involves ferrying a vaudeville troupe. (E) When trouble manages to find him anyway, he handles it so well that he's sent on an extragalactic probe. When he discovers an unexplained barrier, he ends up burying his best friend, delaying the official start of his first 5-year mission by several months, and causing massive head-scratching among astrophysicists and cosmologists, although he does at least find out, without much detail, what happened to the Valiant. ("Where No Man Has Gone Before")