In 1944, a newspaper friend submitted her photo[note 1][7] in the Columbia Pictures "National Cinderella Cover Girl Contest of 1944."

Hart had saved enough money to go to New York when she learned that she was high on the list of Cover Girl finalists.

Although that Dorothy Hart was presented in Sunbrite's advertising as a real person, she was played by Lucy Gilman Scott.

[12] Her first big movie break came, starring alongside Randolph Scott and Barbara Britton in the Western, Gunfighters (1947), a Cinecolor film for Columbia.

Barbara Britton played the female lead in the adventure drama with Hart heading up the supporting cast.

Columnist Hedda Hopper reported in a June 1947 column that Mary Pickford was suing Dorothy Hart for a sum of $79,000 because the young actress refused to accept a role in the film There Goes Lona Henry.

[17] Hart made Larceny (1948), with Shelley Winters and The Countess of Monte Cristo (also 1948) with Sonja Henie, both for Universal Pictures.