British writer Eric Knight created Lassie for a Saturday Evening Post short story in 1938, a story released in book form as Lassie Come Home in 1940. Knight set the story in his native Yorkshire and focused it around the concerns of a family struggling to survive as a unit during the depression. Lassie's original owner Joe Carraclough is forced to sell his dog so that his family can cope with its desperate economic situation, and the story becomes a lesson about the importance of interdependence during hard times. The story met with immediate popularity in the United States and in Great Britain and was made into an MGM feature film in 1943, spanning six sequels between 1945 and 1953. Most of the feature films were still set in the British Isles, and several of them dealt directly with the English experience of World War II. Lassie increasingly became a mythic embodiment of ideals such as courage, faithfulness, and determination in front of hardship, themes that found resonance in wartime with both the British and their American counterparts. Along the way, Lassie's mythic function moved from being the force uniting a family toward a force uniting a nation. The ever-maternal dog became a social facilitator, bringing together romantic couples or helping the lot of widows and orphans.

     In 1954 Lassie made its television debut in a series that removed the dog from Britain and placed her on the American family farm, where once again she was asked to help hold a struggling family together. For the next decade, the Lassie series became primarily the story of a boy and his dog, helping to shape our understanding of American boyhood during that period. The series' rural setting offered a nostalgic conception of national culture at a time when most Americans had left the farm for the city or suburbia. Lassie's ownership shifted from the original Jeff Miller to the orphaned Timmy Martin, but the central themes of the intense relationship between boys and their pets continued. Lassie became a staple of Sunday night television, associated with "wholesome family values," though, periodically, she was also the subject of controversy with parents' groups monitoring television content. Lassie's characteristic dependence on cliff­ hanger plots in which children were placed in jeopardy was seen as too intense for many smaller children; at the same time, Timmy's actions were said to encourage children to disobey their parents and to wander off on their own. Despite such worries, Lassie helped to demonstrate the potential development of ancillary products associated with television programs, appear­ing in everything from comic books and Big Little Books to Viewmaster slides, watches, and Halloween costumes.

     By the mid-1960s, actor Jon Provost proved too old to continue to play Timmy and so Lassie shifted into the hands of a series of park rangers, the focus of the programming coming to fall almost exclusively upon Lassie and her broader civic service as a rescue dog in wilderness areas. Here, the show played an important role in increasing awareness of environmental issues, but the popularity of the series started to decline. Amid increasing questions about the relevance of such a traditional program in the midst of dramatic social change, the series left network television in the early 1970s, though it would continue three more years in syndication and would be transformed into a Saturday morning cartoon series. Following the limited success of the 1979 feature film The Magic of Lassie, yet another attempt was made in the 1980s, without much impact on the marketplace, to revive the Lassie story as a syndicated television series. The 1994 feature film Lassie suggests, however, the continued association of the series with "family entertainment."

     Many animal series, such as Flipper, saw their non­-human protagonists as playful, mischievous, and childlike, leading their owners into scrapes, then heeding them out again. Lassie, however, was consistently portrayed as highly responsible, caring, and nurturing. Insofar as she created problems for her owners, they were problems caused by her eagerness to help others, a commitment to a community larger than the family, and her role was more often to rescue those in peril and to set right wrongs that had been committed. She was the perfect "mother" as defined within 1950s and 1960s American ideology. Ironically, the dogs who have played Lassie through the years have all been male.