The Dana Girls was a series of young adult mystery novels produced by the Stratemeyer Syndicate. The title heroines, Jean and Louise Dana, are teenage sisters and amateur detectives who solve mysteries while at boarding school. The series was created in 1934 in an attempt to capitalize on the popularity of both the Nancy Drew Mystery Stories and the Hardy Boys series, but was less successful than either. The series was written by a number of ghostwriters and, despite going out-of-print twice, lasted from 1934 to 1979; the books have also been translated into a number of other languages. While subject to less critical attention than either Nancy Drew or the Hardy Boys, a number of critics have written about the series, most arguing that the Dana Girls' relative lack of success was due to the more dated nature of the series.
The series' principal characters are Louise and Jean Dana, teenage orphans who solve mysteries while attending the fictional Starhurst School for Girls in Penfield, not far from their hometown of Oak Falls. When on vacation, the girls stay at the home of their guardians, their uncle, Captain Ned Dana, master of the S.S. Balaska, and his spinster sister, Harriet Dana. The household also includes a bungling maid, Cora Appel, often teasingly referred to as "Applecore" by Jean and Louise.
At school, the Dana girls are firmly under the control of the headmistress, Mrs. Crandall, who approves absences from class and other exceptions to the rules only when deemed absolutely necessary to the girls' detective work, however, as the series progresses and mysteries are solved to the benefit of the school, this becomes more and more frequent. Mrs. Crandall often volunteers herself or her husband to assist with investigations, either by driving them, chaperoning them, or at times, actively engaging in activity such as spying from horseback! Her husband, the bookish Professor Crandall, is usually occupied in his study and generally takes no interest in administrative affairs. It is rumored that the professor is engaged in writing a monumental English-language history of Ancient Greece and he is usually left alone by the student body, but the Dana girls discover he can be a useful source of obscure facts relating to the clues in a mystery. He generally takes a less active role in sleuthing than his wife, acting as a driver, escort, or researching a clue academically.