The Mildred Keith Series is a collection of children's novels written by author M. E. (Mildred) Keith. The series follows the life and adventures of a young girl named Mildred Keith as she navigates various challenges and experiences growing up in the late 19th century. The stories often emphasize themes of friendship, family, and personal growth. Set in a time of social change, the series provides readers with insights into the historical context of the era. The books are known for their engaging storytelling and relatable characters, making them popular among young readers and a valuable addition to classic children's literature.