He was apprenticed to the map-engraver Emanuel Bowen, but left before completing his indenture, in consequence of an affair with his daughter, whom he afterwards married.
[1][2] He kept a shop in partnership with Matthias Darly for the sale of caricatures and similar prints,[1] "but the love of pleasure and good company got so much the better of his judgment that he was soon put to other contrivances to obtain a living.
"[3] Having some literary facility, he made money by writing several disreputable novels, such as The Life and Adventures of Benjamin Brass (1765), partly based on his early life, The History of Sir Edward Haunch, and others.
[1] "He wrote for two guineas a set of two volumes; and such was his rapidity, that he could produce one work a week.
After a somewhat vagrant life, Oakman died destitute at his sister's house in Westminster in October 1793,[1] and was buried at Holy Trinity Minories.