He arrived in America in 1869 and settled in Boston, where he established himself as a respected journalist, newspaper editor, novelist and poet, and later helped orchestrate the 1876 Catalpa rescue of six Fenian convicts from Western Australia.
A week after O'Reilly absconded from his convict camp in February, 1869, Johns was captured at the cellars for Houghton Winery in Perth, he was sent back to prison but was given a ticket of leave in 1871.
At the time when O'Reilly published Moondyne, Johns had just married Louisa Hearn in Fremantle and was prospecting for gold near Southern Cross.
Applauded by critics, it was published and republished under a variety of titles including: Moondyne Joe is a convict who escapes after being victimised and mistreated by a cruel penal system.
In the course of this he becomes involved in several subplots including the case of a young woman named Alice Walmsley who has been wrongly convicted of murdering her own child.