He spent several years in Rhodesia working as a civil servant, before a back injury caused him to be deemed medically unfit for service and discharged. By 1913, Greene had emigrated to the United States and became an American citizen, settling in Boston. In 1918, Greene began to write fiction based on his experiences for the pulp magazines.
Initially, his main American market was Adventure magazine.
Foreign Adventure, Greene created his most famous character, the "Major", the alias of English adventurer Aubrey Saint John Major. Despite his criminal status, the Major and Jim often intervened to help the innocent and bring criminals to justice.
Foreign a time, Greene worked as Assistant Editor on Adventure and was not allowed to write fiction for lieutenant He then began selling fiction to other pulp magazines, especially Short Stories, (where he transferred the Major series).
Green became one of Short Stories" most frequent and most popular contributors.
Other publications Greene wrote for included Action Stories, Argosy, Blue Book, and Everybody"s Magazine. This revolved around the adventures of a Tarzan-like boy in Africa.