Roosevelt was born in the former state of Oklahoma, home to the largest concentration of agricultural ranches in the post-War US. His parents adopted him as a baby, and Roosevelt was expected to one day inherit the family business - a sprawling livestock ranch on Oklahoma's tallgrass preserves. Roosevelt thrived in a close-knit community of farmhands and post-apocalyptic cowboys: he learned to shear a bighorner when he was still a child, and was driving brahmin cattle in his early teens. Unfortunately, the Plains Commonwealth was plagued by Caesar's Legion, who staged brutal reprisals against "uncooperative" landowners. One night, whilst its occupants slept, legionaries from the Red Okie Centura set fire to the ranch and surrounding land. Roosevelt escaped with his life, but his family and friends weren't so lucky - not to mention close to a hundred bighorners, who burned alive in their barns.
Were you to meet Roosevelt as an adult, you never would guess that such a traumatic past was less than a decade behind him. Working as a courier for the Mojave Express, Roosevelt was one of many oddballs delivering mail across the continental US. The work was difficult, long hours for what amounted to little pay, but it suited Roosevelt - without the pressure of responsibility, he was free to charm his way across middle America. However, when a routine delivery to the New Vegas Strip took an abrupt turn for the worse, Roosevelt wound up buried in a shallow grave just outside the town of Goodsprings. He was pulled out and nursed back to health by the town's doctor; when he returned to the Mojave Express, it was to find the building empty, and his fellow couriers dead by the same hand that had tried to kill him.
The consummate extrovert, Roosevelt is used to being the center of attention wherever he goes. The life of a courier is good for brief, intense connections, but Roosevelt purposefully shies away from anything long-term. That isn't to say that he's dishonest - on the contrary, Roosevelt is almost painfully genuine - but losing your entire family isn't the kind of thing you can come back from twice. As tales of his heroism spread across the Mojave, its citizens clamor for Roosevelt's attention. If he parties a little too hard, seeks their affection a little too desperately, well, that's just their Roosevelt: the life and soul of the party.