The four series follow Grace Harlowe and her friends through high school, college, abroad during World War I, and on adventures around America. In The High School Girls Series, Grace attends Oakdale High School with friends Anne Pierson, Nora O'Malley, and Jessica Bright.

The four promote fair play and virtue while winning over troubled girls like Miriam Nesbit and Eleanor Savell, playing basketball, and founding sorority Phi Sigma Tau. The group becomes friends with boys in their acquaintance: David Nesbit, Tom Gray, Hippy Wingate, and Reddy Brooks, forming "The Eight Originals."(Introduction by Wikipedia)