Maginn becomes a contributor to Blackwood’s Magazine and, after moving to London in 1824, becomes for a few months in 1826 the Paris correspondent to The Representative, a paper started by John Murray, the publisher. When its short career is run, he helps to found in 1827 the ultra Tory Standard, a newspaper that he edits along with a fellow graduate of Trinity College, Dublin, Stanley Lees Giffard. He also writes for the more scandalous Sunday paper, The Age.
In 1830 Maginn instigates and becomes one of the leading supporters of Fraser’s Magazine. His Homeric Ballads, much praised by contemporary critics, are published in Fraser’s between 1839 and 1842. In 1837, Bentley’s Miscellany is launched, with Charles Dickens as editor, and Maginn writes the prologue and contributes over the next several years a series of “Shakespeare Papers” that examine characters in counter-intuitive fashion. From “The Man in the Bell” (Blackwood’s, 1821) through “Welch Rabbits” (Bentley’s, 1842) Maginn is an occasional though skillful writer of short fiction and tales. His only novel, Whitehall (1827) pretends to be a historical novel set in 1820s England written in the year 2227. It is a droll spoof of the vogue for historical novels as well as the contemporary political scene.
In 1836, Maginn fights a duel with Grantley Berkeley, a member of Parliament. Berkeley had brutally assaulted magazine publisher James Fraser over a review Maginn wrote of Berkeley’s novel Berkeley Castle, and Maginn calls him out. Three rounds are fired but no one is struck.
One of the most brilliant periodical writers of his time, Maginn leaves little permanent work behind him. In his later years, his intemperate habits land him in debtor’s prison. When he emerges through the grace of the Insolvent Debtor’s Act he is in an advanced stage of tuberculosis. He writes until the end, including in the first volume of Punch, but he dies in extreme poverty in Walton-on-Thames, London on August 21, 1842, survived by his wife Ellen, and daughters Annie and Ellen, and son John. His nephew Francis Maginn, who is deaf, is a co-founder of the British Deaf and Dumb Association, now called the British Deaf Association (BDA).