Kathleen Krull is well known for her innovative approach to biographies for young readers. Her books include The Road to Oz: Twists, Turns, Bumps, and Triumphs in the Life of L. Frank Baum; The Boy on Fairfield Street: How Ted Geisel Grew Up to Become Dr. Seuss; the Lives of . . . series of collective biographies; the Giants of Science series; and more, as featured at kathleenkrull.com. Kathleen lives in San Diego, with her husband, children's book illustrator Paul Brewer.

Kathleen Krull proves Sigmund Freud deserves a place in her much-lauded series, because he essentially created a brand-new branch of medicine: psychoanalysis.