John was born to a humble family that migrated to Genesis in 2104 CE and struck it rich working as off-world miners. Kemp, however, was far from satisfied with a life of mining and diplomacy. Like so many others born in the Frontier, he set off looking for something more and eventually found his calling to be the Trailblazer Program.
Kemp did not have an incredibly remarkable career as a Trailblazer, though he always carried himself with the utmost dignity and confidence which netted him a UNSM Commendation. He'd spend most of his twenties training and eventually became one of the first UNSM Marines.
Somewhere along the way, he met his future wife Elizabeth on shore leave and had his only child, Markus, in 2141 CE. John was gone for extended periods with the UNSM, which naturally strained his relationships with both his wife and son.
Yet, in 2147 CE, the two were caught in an car accident on the Intergalactic Assembly Station that resulted in his wife's death and near loss of his son. The incident opened his eyes and prompted his transfer from Marine life to one of an officer, where he could personally oversee and raise Markus to the best of his ability.
Over the next 30 years, Markus grew to be a remarkable leader and John came to be the Fleet Admiral, but their relationship suffered. Their infighting is no secret among the UN Navy and came to be a prominent story line in Human media in the '70s.