The first season of the American television drama series Mad Men premiered on July 19, 2007, and ended on October 18, 2007. It consisted of thirteen episodes, each running approximately 47 minutes. AMC broadcast the first season on Thursdays at 10:00 pm in the United States. Actors Jon Hamm, Elisabeth Moss, Vincent Kartheiser, January Jones, Christina Hendricks, Bryan Batt, Michael Gladis, Aaron Staton, and Rich Sommer receive main cast billing.

Season one takes place between March and November 1960. It introduces the fictional advertising agency Sterling Cooper. The season begins with the new secretary, Peggy Olson, starting her first day with the firm. As the season unfolds, the mysterious backstory of enigmatic ad man Don Draper is revealed as is the growing confidence and success of Peggy Olson.

The first season was highly commended for its excellence in writing, acting, and art design, as well as for its faithfulness to the era it depicted. It was acknowledged with numerous honors from industry awards, including the Primetime Emmy Award for Outstanding Drama Series, the Golden Globe Award for Best Drama Series, and a Peabody Award. According to Metacritic's annual aggregate of year-end lists that detailed the best TV shows of 2007 as determined by significant entertainment publications and critics, Mad Men's first season received the most mentions of any show and also received the most first-place votes.^[1]

The first season opens in March 1960, as genius advertising executive Donald "Don" Draper meets Peggy Olson, his new secretary. They both work at the small but prestigious agency Sterling Cooper. Though Don is welcoming towards her, Peggy is subject to passive-aggressive hostility from office manager Joan Holloway and sexual harassment from her male colleagues. Junior accounts manager Pete Campbell, who is about to get married, takes a liking to Peggy and the two have sex the night of his bachelor party. Don, meanwhile, has trouble balancing his life as he cheats on his wife, Betty Draper, with a beatnik artist named Midge Daniels. Roger Sterling, the acerbic son of one of Sterling Cooper's founding partners, cheats on his wife, Mona, with Joan, of whom he is enamored.

Sterling Cooper begins working for the 1960 Richard Nixon presidential campaign, gratis and unbidden, as they believe Nixon's success against John F. Kennedy will benefit their business. They are also working to reassure their largest client, Lucky Strike, whose account is the firm's bread and butter, in the face of resurgent medical research demonstrating smoking is harmful and related lawsuits and impending legislation harmful to the tobacco industry.

Betty begins seeing a psychiatrist after her numb and shaking hands cause her to crash the family car. Don, initially resistant to the idea of psychotherapy, allows Betty to seek help. Behind Betty's back, Don has Betty's doctor report back to Don what Betty says in treatment. Meanwhile, Don begins a flirtatious relationship with Rachel Menken, the Jewish owner of a department store who seeks marketing help at Sterling Cooper.

Don also has to deal with the arrival of his younger brother, Adam Whitman, who refers to Don as "Dick Whitman". Don gives Adam $5,000 and tells him to make a new life for himself, as Don did, and to never contact Don again.

Flashbacks to Don's childhood as "Dick Whitman", during the Great Depression, depict Dick's relationships with his unloving, pious stepmother, who calls him a "whore-child", and abusive father Archibald Whitman, who cheats a hobo out of promised payment for performing chores. Dick had grown friendly with the vagrant, and the incident further degrades his image of his father. Additionally, the vagrant teaches young Dick the hobo code, which communicates important messages via simple visual symbols. Don finds a weathered hobo sign indicating Don's father is a dishonest man.

Peggy begins writing copy after ad man Freddy Rumsen recognizes her talent. She is soon given control of her own account, creating a campaign for a weight loss machine. Peggy's work on the weight loss machine coincides with her own weight gain.

Roger suffers two heart attacks, drastically changing his outlook on life, and prompting Lucky Strike's owner, Lee Garner, Sr., to warn Bert Cooper that keeping Lucky Strike's account requires Sterling Cooper to do something to "show Don Sterling Cooper appreciates him". Bert then offers Don a partnership, with a 12% share of the business (without Don having to pay a partnership fee). Don accepts, provided he's not required to sign a contract; an amused Bert agrees, and acknowledges Don's attitude calls back to Ayn Rand's philosophy, as expressed in the book Bert had earlier urged Don to read: Atlas Shrugged.

Don's first order of business is to appoint a new head of accounts (to lighten Roger's load as partner and rainmaker), and Don begins interviewing external candidates (to Pete's chagrin). The most promising candidate proves to be Herman "Duck" Phillips, who "landed American Airlines", but is looking for a job after alcoholism and an extramarital affair ended his career at Y&R's London office.

After the partners leave for the day, the Sterling Cooper ad men throw a raucous party the night of the 1960 presidential election, but see their client and preferred choice, Nixon, defeated by Kennedy.

Further flashbacks revolve around Dick Whitman's origin story in the Korean War, in which he is put under the command of a Lieutenant Donald Draper, who is soon to be sent home. After an attack, an accidental explosion kills Draper and injures Whitman. Whitman switches dog tags with his lieutenant and assumes Draper's identity as a way to escape the war. The Army has "Draper" take Whitman's body back to Whitman's family. The coffin is dropped off by train, and Whitman does not exit to greet his family, but a young Adam sees Whitman standing inside the train. Adam's parents dismiss his entreaties that, "I see Dick on the train". A female train passenger notices Whitman's look of grief and tells him to "forget that boy in the box". Whitman then turns his back on his family and begins his new life as "Donald Draper".

Pete, who has demonstrated a propensity to snoop, expresses the belief that he should be promoted to head of accounts and throws his hat in the ring. He has also revealed his jealousy about Peggy and Don's success and sits at Don's desk after the two have left for the day. The mailroom boy mistakes Pete for Don and delivers a package from Adam Whitman filled with Dick Whitman's dog tags and childhood photographs. (Adam posted the package immediately before hanging himself in his hotel room).

Pete confronts Don with the information that he knows Don's real name is Dick Whitman and attempts to blackmail him for a promotion. Don neutralizes the threat by telling Bert, "I've pulled the trigger on hiring Duck Phillips," which he knew would incite Pete to reveal Don's true identity to Bert. Pete tells Bert that Don is a deserter who isn't who he says he is, but Bert brushes it off with "Who cares?" After Pete leaves the room, Bert gives Don the option to either fire Pete or keep a close eye on him, as "one never knows how loyalty is born."

Peggy seeks medical care for severe stomach pain. The doctor quickly realizes Peggy's weight gain is a result of a pregnancy; she was impregnated by Pete Campbell. After the child is delivered, the nurse encourages Peggy to hold the baby, but Peggy refuses.

The season ends just before Thanksgiving 1960, as Betty and Don bicker over Don's lack of interest in attending Thanksgiving dinner with Betty's family. Don cites his workload as his reason to stay home. Soon afterwards, Betty discovers Don was receiving calls from her psychiatrist, who was reporting on her sessions to Don. Don also learns that his brother Adam has hanged himself.

Don subsequently makes a new campaign presentation for the Kodak Carousel that revolves around the "power of nostalgia".

During a train ride, Don has a vision of returning home to announce he will be joining the family for Thanksgiving. Instead, Don returns home to find the house dark and empty. He sits alone at the bottom of the staircase as the season closes.

The first season was released on DVD and Blu-ray in region 1 on July 1, 2008. In addition to the thirteen episodes, the discs include 26 audio commentaries by cast and crew, and featurettes regarding the production of the series and mini-documentaries on media culture and the historical time in which the story is set. Featurettes include "Establishing Mad Men", "Advertising the American Dream", and "Scoring Mad Men". Also included is a music sampler for music from the show, a photo gallery, and a season two preview.^[49][50]