The first group consists of Books 1–39, in which Morgan Le Fay sends Jack and Annie Smith, siblings from the fictional small town of Frog Creek, Pennsylvania, on adventures and missions through a magical tree house.
Kathleen and Teddy are apprentices who befriend Jack and Annie and provide support, occasionally joining them on adventures.
[1] Mrs. Osborne spent time in Crete and traveled through Iraq, Iran, India, Afghanistan, Turkey, Lebanon, Syria, and Pakistan.
[2] The trip ended when Mrs. Osborne experienced blood poisoning in Nepal and was hospitalized for several weeks, during which she read The Lord of the Rings.
"[3] The book served as the starting point for Mrs. Osborne's writing career; her early work received mixed reviews.
"[2] When Mrs. Osborne started writing the series, she wrote Jack as a main character and added Annie as a typical annoying younger sister.
[11] According to the original illustrations by Sal Murdocca, Jack has brown hair, wears red glasses, and is taller than Annie.
[10] According to the original illustrations by Sal Murdocca, Annie is depicted as having medium-length blonde hair, often worn in double braids, and bangs.
[18] She was profiled on NBC's Rock Center with Brian Williams for her continued efforts to give children books while on a Magic Tree House-themed tour bus.
[24] In 2011, Will Osborne collaborated with New Orleans composer Allen Toussaint and Ain't Misbehavin' co-creator Murray Horwitz to write A Night in New Orleans, a musical adaptation of A Good Night for Ghosts about the life of Louis Armstrong which features an ensemble cast and live jazz band.
[26] To date, children's shows have been created by husband and wife playwright and composer team Randy Courts and Jenny Laird[27] in collaboration with Will Osborne based on Dinosaurs Before Dark, The Knight at Dawn, Pirates Past Noon, A Ghost Tale for Christmas Time,[27] and A Night in New Orleans.
[22] The animated film Magic Tree House (マジック・ツリーハウス, Majikku Tsurī Hausu), produced by Media Factory, premiered in Japan in October 2011[28] and was released there on January 7, 2012.
[30] The Magic Tree House: Merlin Missions were originally ordered sequentially, starting at Book #29 (Christmas in Camelot).
The Magic Tree House Fact Trackers (formerly called Magic Tree House Research Guides) are non-fiction companions to the fiction books written by Mary Pope Osborne, Will Osborne, and Natalie Pope Boyce, which provide more in-depth information on topics featured in the series.