That Girl was reputedly inspired by the life of its star, Marlo Thomas. The daughter of famous television comedian Danny Thomas wanted success on her own merits, so she moved to Britain, where her father was unknown. After five years struggling, she won acclaim in Mike Nichol's 1965 London production of Barefoot in the Park. Returning home, she starred in an ABC pilot, Two's Company, about a model married to a photographer. Although it was not picked up, ABC head Ed Sherick offered Thomas other roles. including the lead in My Mother, the Car. She rejected these parts and instead approached the network with an idea for a show called Miss Independence, centered on the life of a young, single career woman. ABC was interested but wanted some kind of chaperone as a regular character. Like The Patty Duke Show, Peyton Place, and Gid­get, That Girl was one of many shows ABC targeted at the  young  female  audience  during  the  mid- to late 1960s. The network had successfully turned to this up­ -and-coming demographic as early as 1963, capitalizing on the nascent women's movement and youth revolution. Like most of these shows, That Girl followed an already established trend, offering a diluted and sanitized version of the glamorized single-woman lifestyle popularized by the likes of Helen Gurley Brown. Mary McCarthy, and Jacqueline Susann. Unlike those writers' heroines, however, Ann Marie remained, at the behest of network standards and practices offices, chaste. The executives even wanted her to marry steady boyfriend, magazine executive Don Hollinger (whom she met in the first episode), but Thomas resisted, consenting only to a September 1970 engagement.

While it focused on a self-supporting woman, That Girl did not center on the workplace (unlike The Mary Tyler Moore Show), largely because Ann's employment was essentially itinerant. Instead, her efforts to succeed revealed a merging of public and private life. The erratic nature of her employment undermined everyday routines of working life, positioning  her  independence as highly  precarious-particularly  when  contrasted  to the steady rituals of Don's career. Ann’s temporary jobs presented comedic opportunities as she struggled to retain her dignity in the face of often demeaning circumstances while foregrounding her continued reliance on her parents and Don. Female independence was thus presented as a site of struggle, both against the restrictions of the male-dominated workplace and the  social and familial pressures for marriage. Meanwhile, Ann's very choice of profession-the stage-undermined her desire for success, casting it in terms of  fantasy. This lack of realism was evident from  the  start.  Even Thomas noted that her struggling actress heroine never changed or developed. This refusal of change ultimately led to the show's 1971 cancellation: despite good ratings, Thomas announced that  she  could  not face playing the same character for eternity.