"The Maple Leaf" magazine was established in Oakland, California by Michael Ambrose McInnis in February 1907. McInnis was born in Seven Mile Bay, Prince Edward Island, on 23 November 1863. He began working as an apprentice at the offices of "The Journal Pioneer" in Summerside at the age of 16. After his mother's death in 1889, he emigrated to California where he found work in a printing shop. A few years later, he opened his own shop in Oakland. By 1906, he and his partner, Walter V. Harrington, had prospered greatly and began publication of "The Maple Leaf" the following year.

For McInnis, the purpose of the magazine was to enable transplanted Maritimers in California to keep in touch with their roots and to provide those back home with information concerning the whereabouts and activities of their distant family members. Material for the magazine came from Maritime newspapers, contributions from readers, and visitors to the McInnis home. McInnis continued publishing "The Maple Leaf" until his death in March 1947. The last issue, March-April 1947, was published shortly after his death.