Moriarty, 50, has been in the United States nearly his entire life, and arrived in the country as a child.  He claims that his grandfather helped found the original settlement a few years after the war. His father used the nearby trade routes to amass wealth, which is used to help secure Megaton. Colin inherited this wealth when his father was killed during a raider attack when Colin was 14. Colin's first move was to build a fence around the town. Since then, the people have looked to Colin as a benefactor despite his running drinks, chems, girls, and games out of his saloon. Lucas Simms turns a blind eye to Moriarty's activities, because he is acutely aware that the town needs Colin's support and resources.
According to Andy Stahl, Moriarty urinates in his bar's still. Moriarty is also very knowledgeable about information regarding the townspeople, and is always keeping tabs on them in case he needs to blackmail them later. He comes off as a very proactive businessman, extorting caps from whoever possible.
Following in His Footsteps: He tells the player where their father is and recalls the time he saw the player character as a child. If the player character tells Moriarty they don't have 100 caps to buy information on James, he will ask them to find a woman called Silver and get his money back.
"Is that what your father told you? That you were born in that hole? That HE was born there as well? Oh, the lies we tell to those we love. Your father brought you to the Vault right after you were born. To keep you safe, you see. I remember it well -- you stayed in my saloon, after all."