Mathiu Carter was born a farm boy on the outskirts of Tallahassee. In his youth, he was taught outdoor skills such as hunting and shooting by his grandfather, skills which would later prove useful as a marshal. Carter was good at schoolwork, working farm equipment, and learned how to drive multiple vehicles. His father taught him how to brawl, and to stand up to bullies. Carter would later say that his father taught him where to draw the line, rather than to take a stand. The first eighteen years of his life were quite "adventurous" as many would describe it.
Carter started off as an EMT, training in the medical field for sometime but his passion lead him elsewhere.
Eventually leading up to become a US Marshal, Carter chased after high priority criminals that caused havoc in society. Folks say the crime rates decreasing were very noticeable.
"Mathiu Carter was the most decent man I ever encountered during the start of the infection. Everyone else, I can safely say, was either a victim or a villain or quite often both. At first glance, Carter seems like a backwoods cowboy, one of those good old boys swapping lies about the days gone by. There's a cocksureness, an overconfidence about him that makes you bridle initially. Yet over time you come to see him as a valuable ally and — dare I say it? — a friend. It all comes from belief. Mathiu Carter believed in himself and believed in those around him. And from that strength came the strength that allowed him and those who followed him to survive everything else the universe threw at him. Mat Carter was a most decent and honorable man. I suppose that's why his is the greatest tragedy in this godforsaken world." -Quote from City Mayor
What lead him to Chernarus was the fact his mother's side of the family is from Chernarus. Losing his family from the rampant attacks from the infected, Carter set off to find what family he had left on the other side of the planet.