At the height of the Potato Famine in Ireland, an abortive nationalist revolt against English rule is crushed by a government police detachment in Tipperary. In a brief skirmish in a cabbage patch, Irish nationalists under William Smith O'Brien were overcome and arrested. The nationalists, members of the Young Ireland movement, had planned to declare an independent Irish republic, but they lacked support from the Irish peasantry, who were occupied entirely with surviving the famine.
By the mid-19th century, the Irish population, which suffered under the system of absentee landlords, had been reduced to a subsistence diet based largely on potatoes. When a potato blight struck the country in the 1840s, disaster ensued. Between 1846 and 1851, more than one million people starved to death, and some two million people left the country, mostly to America. With the desperate times of the famine came an increased radicalism in the Irish nationalist movement.
In 1846, O'Brien formed, with John Mitchel, the Irish Confederation, a branch of the Young Ireland movement dedicated to freeing Ireland by direct action. By 1848, the group was calling for open rebellion against the English, but Mitchel was arrested, convicted of sedition, and transported to a prison colony in Australia before the revolt could begin. Aggravated by the worsening potato famine and Mitchel's arrest, O'Brien launched an unsuccessful uprising on July 29, 1848. He was arrested and sentenced to death for treason, but his sentence was commuted to transportation to the penal colony at Tasmania.
After the failure of the Young Ireland revolt, many embittered Irish nationalists immigrated to the United States, Australia, and Canada, where they redoubled their agitation against England.