Donald Francis Draper is revealed through flashbacks to be the assumed identity of Richard "Dick" Whitman, born in Bunbury, Illinois, in May 1926 to Evangeline (Kelly Huddleston), a prostitute, and an abusive, alcoholic farmer, Archibald "Archie" Whitman (Joseph Culp). His mother Evangeline died in labor, and the midwife brought the baby to be raised by Archie and his wife, Abigail.
When he was 10 years old, Dick saw his father Archie die after being kicked by a spooked horse. He began to suffer from croup and was left under the care of a prostitute named Aimée (Megan Ferguson). She took his virginity in a way that creator Matthew Weiner stated concerned "his relationship to sex and molestation", and reviewer Abigail Rine described more directly as rape.
Dick Whitman briefly served in the Korean War, where he was injured in a gasoline explosion where his commanding officer, Lieutenant Donald Draper, was killed. Dick switched dog tags with the unidentifiable body of Lieutenant Draper and assumed his identity, thus reinventing himself as Don Draper.
The new Don Draper relocated to New York City, where he worked as a fur salesman and attended City College at night. With the support of his boss, he wrote advertising copy for the fur company, helping him build a portfolio along with some spec ads. At this job in 1953 Draper met his future wife, Elizabeth "Betty" Hofstadt (January Jones), a model who was photographed for one of his own ads. After meeting Roger Sterling at the fur store and a subsequent boozy lunch meeting, Draper assumed a job at Sterling Cooper, where he eventually became creative director.
He was considered a major asset to the company, as he had considerable talent for understanding the desires of others and for effectively pitching and selling ideas. Because of this, he was occasionally courted by other advertising firms. Although he kept his true identity heavily guarded, almost everyone at the firm was portrayed as respecting his talent. At the same time, many in the firm were also troubled by Draper's erratic behavior.
His marriage was rocky, with Draper having numerous affairs. Betty filed for divorce in 1964 after she discovered his true identity; Betty later married Republican political operative Henry Francis (Christopher Stanley). As his marriage was ending, Draper also left Sterling Cooper due to its impending sale to McCann Erickson, becoming a name partner in the new firm Sterling Cooper Draper Pryce. After his divorce and Betty's remarriage, Draper began to grow increasingly dependent on alcohol. He entered a relationship with a colleague, Dr. Faye Miller, but eventually married his secretary, aspiring actress Megan Calvet (Jessica Paré). In the summer of 1966 they moved to a stylish apartment on Park Avenue in the Upper East Side. His marriage to Megan lasted until 1970.