Mitchel was born in Camnish, County Derry in 1815. The son of John Mitchel, a radical Presbyterian minister with strong Unitarian sympathies, and his wife Mary Haslet. Mitchel was educated in Newry and Trinity College Dublin. After a period as a bank clerk he began working as a solicitor in Banbridge in County Down in 1840. In 1845 he abandoned law to join the staff of the nationalist newspaper The Nation.
Mitchel's radicalism was too extreme for the newspaper and led to the prosecution of the paper's editor, Charles Gavin Duffy for seditious libel. In 1848 Mitchell set up his own newspaper, the United Irishman, where he called for rebellion against British rule in Ireland and criticised British mismanagement of the Irish Potato Famine. Mitchell's calls led to a charge of sedition. He was convicted under the emergency powers provisions of the recently enacted Treasury Felony Act and sentenced to 14 years imprisonment in the penal colony of Van Diemen's Land. It was during this period he wrote his famed Jail Journal, in which he expressed his hatred of Britain and his more radical brand of nationalism than generally had little mass appeal in mid nineteenth century Ireland, where constitutional nationalists such as Daniel O'Connell, Isaac Butt and Charles Stewart Parnell dominated, with more radical nationalists advocating violence relegated to launching the occasional unsuccessful rebellion on the sidelines (eg, the Young Ireland rebellion of 1848 and the Fenian uprising of 1865).
Mitchell escaped from the colony in 1853 and established the radical Irish nationalist newspaper The Citizen in New York, as an expression of radical Irish-American anti-British opinion. The paper however became controversial for its passionate defence of slavery. Mitchell, a critic of international capitalism, which he blamed for the Irish Famine, saw the southern states' economies with their reliance on slavery, as offering an alternative form of economic and social organisation to the form of international capitalism he despised. Mitchel resigned from the paper and toured as a spokesman for the south, founding a new paper, the Southern Citizen as a mouthpiece for the cause of slavery. Mitchel fell out with Jefferson Davis, who he regarded as too moderate. Mitchel ended up back in prison for a short time in 1865.
With the ending of slavery and the victory for the Union side in the American Civil War, Mitchel returned to agitation on the issue of Ireland. He founded his third American newspaper, the Irish Citizen but contrary to the expections of radical Irish-Americans Mitchel declined to support the radical Irish revolutionary group, the Fenians, nor as moderates hoped, with the cause of Irish home rule, instead using the paper to public what purported to be a continuation of his Jail Journal but was in reality a further expression of his pro-slavery views. The paper failed to attract readers and folded in 1872.
Mitchell returned to Ireland where in 1875 he was elected in a by-election to be an MP in the British parliament representing the Tipperary constituency. However his election was invalidated on the grounds that he was a convicted felon. He contested the seat again in the resulting by-election, again being elected, this time with an increased vote. However his sudden death avoided a constitutional crisis, with his opponent being returned unopposed in the third by-election.
Mitchell remains a famed figure in Irish history for his involvement in radical nationalist agitation, and in particular for his Jail Journal. His role in defending slavery however remains relatively forgotten except by historians of American history. Deportation and the Jail Journal
Pro-slavery campaigner in the United States
Elected an MP