James "Sawyer" Ford is a con man born in Alabama who assumed the name of the man who conned his mother out of all of the family's money. After this happened, Sawyer's father killed his mother and himself. Sawyer vowed since he was a child to find the man named Sawyer, who ruined his parents' lives. In his adult life, Sawyer became a con man who has duped many women out of thousands of dollars. He typically plays the romantic angle on his cons and this resulted in fathering a child with one of the women, Cassidy. The child, a daughter, was named Clementine and he's never met her.
On the island, Sawyer is gruff and initially disliked by many because of his acerbic personality. He doesn't really trust anyone and keeps his distance, and has a habit of giving nicknames to people he meets -- typically not terribly flattering ones. He, at first, hoards things like whiskey and porn that he's stolen from the wreckage of the plane, and manipulates his fellow survivors. He once claimed to have Shannon's asthma medication and said he'd reveal where it was if Kate kissed him. After she did, he admitted he never had the medicine. He seems to lack the ability to communicate and work with others, at one point even saying, "every man for himself" when he is asked to help Jack out of a sticky situation. He has a rivalry with Jack, thanks to their mutual attraction to Kate, and they have very different styles. Sawyer, for example, aims to gain access to any weapons on the island so that he can use and control them, while Jack looks to collect and lock them up so they won't be misused and the group can have them if and when they need to defend themselves.
Over time, despite hanging on to his hard exterior, Sawyer becomes more friendly and trustworthy. He also becomes a hero to some, once sacrificing his spot on what is believed to be a way off the island. Sawyer is often depicted reading books, which seems to fly in the face of the ultra-rugged persona he's developed. He is also very protective of Claire and her baby Aaron.