The founder of McGlynn's Bakery was James T. McGlynn (or J.T. as most everybody called him). James was an accountant; he only attended school through sixth grade. In 1919 while working as an accountant, J.T. bought a small bakery in Minneapolis. He renamed it McGlynn's Bakery. Shortly before that he was traveling in Montana on a business trip, and met his future wife, Mary Byrnes, who was a school teacher in Webo, Montana.
J.T.'s family came to America from Ireland during the potato famine. His parents settled in the New Jersey area. During one of the frequent health plagues, tragically all five of their children died (they were all daughters). J.T.'s parents moved to Minneapolis and had five sons; J.T. was one of them. J.T.'s father died after they moved to Minnesota. All the sons had to work to help support the family.