Kate Hannigan used to work for daily newspapers, but now she writes fiction and nonfiction for young readers, digging up information on remarkable people from history and sharing their stories. Her work includes a historical fantasy series for middle grade readers, The League of Super Heroes; the historical mystery The Detective's Assistant; and a picture book biography of Belva Lockwood, A Lady Has the Floor. Kate lives in Chicago, not far from the Columbian Exposition site, and shops near Mrs. O'Leary's old home.

Josh Rosen is a Toronto-based cartoonist and illustrator. A graduate of the Center for Cartoon Studies, Josh has done illustration work for magazines, animation projects, documentary films, and tabletop role-playing games, as well as a slew of small-press comics work. His first graphic novel, The Good Fight, with author Ted Staunton, was long-listed for the Toronto Book Awards. He enjoys making comics about spooky stuff, nerdy stuff, and real-world history. When not actively drawing, Josh works in children's arts and literacy education.