Over the years, there has been much speculation over whether characters that Lewis wrote about in his novels were based on real people. It is true that Lewis's fiction often contains similarities to Lewis's own life. Sauk Centre, Minnesota, Lewis's hometown, boasts that it is the "real" Gopher Prairie.
Sally Parry's essay, "The Changing Fictional Faces of Sinclair Lewis's Wives," notes many similarities between Lewis's wives and the female characters in his novels. Lewis's first wife, Grace Hegger, appears in idealized form as Ruth in The Trail of the Hawk and Una Golden in The Job. Grace also seems to have inspired Carol Kennicott's character in Main Street (though Carol also has some of Lewis's attributes).
In Dodsworth, Grace is similar to Fran Dodsworth, and the romantic triangle among Sam Dodsworth, his wife Fran, and Edith Cortright is based to a certain extent on Lewis's own life. In the late 1920s, Lewis was separated from his first wife Grace and met journalist Dorothy Thompson in Europe. He eventually divorced his wife and married Thompson, whom he divorced in the 1940s. Some critics have seen Dodsworth as a stand-in for Lewis, although certainly Dodsworth would have been an idealized version of Lewis. Fran is probably closest to her real life counterpart. When the stage play of Dodsworth was done in the 1930s, Lewis supposedly attended rehearsals and at one point called out to the actress playing Fran, "Come on, Gracie, you can be much bitchier than that!" (Schorer 596).
In addition to Edith, Thompson also influenced the character of Ann in Ann Vickers. Ann and Thompson seem similar in general demeanor and achievement in their fields. However, Winifred Homeward, the Talking Woman in Gideon Planish (1943), negatively parodies Thompson. Lewis's mistress, Marcella Powers, is idealistically portrayed as Bethel in Bethel Merriday (1940). Jinny Timberlane in Cass Timberlane also bears a striking resemblance to Powers.
Lewis's own reaction to his son Wells's birth is alluded to in The Trail of the Hawk, when Carl compares the idea of having children to a limitation on his freedom. In Arrowsmith, Martin Arrowsmith leaves his wife and son, telling his child to, "Come to me when you grow up, old man" (443).