I would like to begin by explaining that I do not have correspondence from many of the siblings. The best way I feel I can answer this question is to write the answers I have and where they come from. I will let each of you decide what you think.
On August 30, 1957, Allene Jensen, interviewed John and his sister Belle about the success of Papa Married a Mormon. In the second paragraph she writes
John Fitzgerald in collaboration with his sister, Belle Fitzgerald Empey, wrote the recent best seller, Papa Married a Mormon. Mrs. Empey says her name is not included on the book because of its being written in the first-person. An account of their family's life in pioneer Utah together with a good-natured lesson in religious tolerance, made it an overnight hit.
In 1989, John's niece, Shelly, was working on a project connected with his books. She wrote her Uncle Gerald. I do not have the letter she wrote, but I do have his answers. Please remember Gerald was the baby of the family.
John D. left Price after high school and came back infrequently, while I was there. Once in 1928, after he had been around the world working for a news organization. Then he left again and was back east, Later in Calif. he sold Steel and planned two Write "Papa Married a Morman" in conjunction with Belle. She did most of the research. Primarily all of his books were 90% fiction. John was a great story teller. For the most part he was the "Great Brain".Shortly after that letter, Shelly and Gerald's son John, wrote a fan letter to send to the many fans who wrote them. In the letter she wrote
John D. Fitzgerald was born and raised in Price, Utah and was the fourth of six children. He really did have an older brother named Tom whom everyone in town knew as the "Great Brain". There were no computers or televisions back then but Tom made life exciting and fun. Uncle John wrtoe a number of books for adults including the best seller "Papa Married a Mormon." However, it was not until later in life that John decided to write for children. He invited some friends over for dinner one night and told them about his brother Tom and all of his great adventures. The friends enjoyed the stories so much that Uncle John decided to write "The Great Brain".
In 1989, a disgruntled Price citizen wrote a rebuttal to a complaint in the paper. A portion of it reads as such,
I went to school with Gerald Fitzgerald and we became good friends....I became very well acquainted with William "Bill" to all of us he was an expert electrician. Also Thomas "Tom" who everyone knew as "The Great Brain". Tom was a painter and a great philosopher was able and willing to talk on any subject a great friend of mine.
Some years later a student, Ryan Madsen, interviewed Gerald about the books. When Ryan asked about if John was really the Great Brain, Gerald again said, "yes".
By the time I began my research, Gerald was the only living member left of Papa and Mamma's family. He was 91 years old and living in a retirement home. His son John kindly answered my questions (at the time I didn't have all of the information I just shared with you, nothing came in chronologically). When I asked if the family was happy with the books, he wrote the following,
I'm not sure what you mean. The books contain stories that combine truth and fiction. The general story in Papa Married a Mormon is true, but specifics may be made up. In the Great Brain, happenings were typical of things that happened but names and dates and particular incidents may be made up. I think the family viewed the portaryals as stories based on experiences. I think the brothers were all proud of John.One of my final questions concerned, Tom. John replied,
Uncle Tom lived out his days in a small apartment in Price. He loved to read and was surrounded by books. It is not clear that Tom was the "Great Brain". According to my dad. The Great Brain books combine incidents that happened to each along with some fictionalized incidents. My dad always thought John himself was more the model for the Great Brain.These are the only answers I have. I have my own opinions, but I will let you decide for yourself. Charles thanks for the question.