Mary Louise and the Liberty Girls

The Bluebird Books is a series of novels popular with teenage girls in the 1910s and 1920s. The series was begun by L. Frank Baum using his Edith Van Dyne pseudonym, then continued by at least three others, all using the same pseudonym. Baum wrote the first four books in the series, possibly with help from his son, Harry Neal Baum, on the third.
The object of this little story is not especially to encourage loyalty and devotion to one's country, for these are sentiments firmly enshrined in the hearts of all true American girls. It is rather intended to show what important tasks girls may accomplish when spurred on by patriotism, and that none is too humble to substantially serve her country.