Duffy was born in
Monaghan. He was educated at a hedge school and began his business as a bookseller through purchasing Protestant bibles given to Catholics. He then traveled to
Liverpool where he traded them for more valuable books. In 1830 he founded his own company,
James Duffy and Sons and issued ''Boney's Oraculum
, or Napoleon's Book of Fate
, which experienced huge sales. Boney's Oraculum'' would later be the object of an allusion in a speech of Capt. Boyle in
Seán O'Casey's 1924 play
Juno and the Paycock. Another great editorial success was achieved when he collaborated with
Charles Gavan Duffy (no relation) from 1843 to 1846 to publish poetry from the writers of
The Nation. By the 1860s he was employing 120 staff members at his various enterprises in Dublin. •
The Spirit of the Nation. Ballads and Songs by the Writers of
The Nation, with Original and Ancient Music (1845) •
The Poetry of Ireland. Further collections from the writers of The Nation (1845-1846) •
The Ballad Poetry of Ireland •
The Book of Irish Ballads • an 1861 edition of the
Douay Bible, a copy of which is owned by the
Central Catholic Library in Dublin • John O'Hart,
Irish landed gentry: when Cromwell came to Ireland (Dublin: James Duffy & Sons, 1887) • John O’Hanlon,
Lives of the Irish Saints, Vol 6 (James Duffy and Sons, 1891) • Gerald Griffin
The Invasion (Dublin, James Duffy & Sons) Books series he published included: • Duffy's Cabinet Library • Duffy's Library of Ireland • The Orators of Ireland • ==Publishing House==