Emmett McCarty was born in 1915 and grew up in the small town of Gatlinburg, Tennessee, part of a large Scotch-Irish family. He had what his parents considered a wild adolescence, never one to worry about consequences and preferring to gamble, drink, and womanize. However, he was a loving child of his family who always kept them supplied with games. He worked on the railroad with his older brothers in Gatlinburg, while his younger 14 year old sister would help their mother with housework.
Emmett was changed into a vampire by Carlisle Cullen in 1935, two years after Rosalie Hale had been changed. When Rosalie came across him, Emmett was being mauled by a black bear in the mountains of Tennessee. He had nearly died from the attack, but Rosalie saved him and carried him over a hundred miles back to Carlisle. Rosalie was noted as saying that it took nearly all her strength not to kill him. She also said that she brought him to Carlisle so that he, with his stronger endurance to human blood, could save Emmett, being afraid that she would kill him instead. Emmett describes this experience as "being saved by an angel who brought him to God". Many years later, Rosalie confessed to Bella that she saved Emmett from dying because of his innocent look, dimples, and curly hair that reminded her of her best friend Vera's child, Henry, and that ever since the day she saw the baby she always wanted a child of her own just like him. While going through the change, Carlisle attempted to inject painkillers into his system to numb the pain, but the venom burned it out before it could spread.
After his painful transformation, Rosalie and Carlisle explained to Emmett that he was a vampire. This did not upset him, however, like Rosalie and Carlisle had thought it would. He put in his own words, "Hell's not so bad if you get to keep an angel with you." As he still cared for his natural family and knew that he could no longer go back, he had Edward prepare a bag of fortune in hopes to ease their pain of losing a hardworking son and personally left it on the porch. He hadn't looked back since then. He did, however, initially have trouble adjusting to the Cullens' rule of only feeding on animals, and has tasted human blood on several occasions. The Cullens were forced to move around for this reason. He had even run into two strangers whose blood appealed to him like Bella's to Edward, causing him to lose control. Emmett married Rosalie before Alice and Jasper joined their family.