Griffith's message attracted many Irishmen and Irish-women, most of them radicals, who were frustrated by the failure of Westminster-based politics to advance Irish nationalism. The Sinn Féin League (its title until 1908) grew rapidly, often by absorbing other radical groups. It did not impress Irish Parliamentary Party leader John Redmond, however. After his party's candidate defeated Sinn Féin's first parliamentary candidate in 1908, he dismissed the group as "a temporary adhesion of isolated cranks."
Sinn Féin opposed Irish enlistments into the British Army during World War I but had nothing to do with the 1916 Easter Rebellion. The British government believed otherwise because of the group's radical reputation and undeniable influence on Irish politics, and London referred to the revolt as the "Sinn Féin Rebellion."
In late 1917, Sinn Féin became what the British thought it was a year earlier: the political arm of Irish republicanism. With Eamon De Valera, one of the surviving leaders of the Easter Rebellion, as its president, Sinn Féin quickly became a well-organized and effective national political party but did not became more popular than the long-established Irish Parliamentary Party until the 1918 Conscription Crisis, sparked by the British government's threat to impose a military draft on Ireland. In December 1918, Sinn Féin won 73 of Ireland's 105 Westminster seats and, as Griffith had exhorted, refused to go to London. Instead, the elected members of Parliament established the Dáil Éireann as the legitimate government of the Irish Republic proclaimed in 1916.
Irish republicanism—and its political and military institutions, Sinn Féin and the Irish Republican Army (IRA), respectively—split over the 1921 Anglo-Irish Treaty. Led by De Valera, the antitreaty forces walked out of the Dáil and into civil war. These republicans, however, did not accept their 1923 defeat at the hands of the protreaty republicans, who adopted the name Cumann na Gaedheal (Legion of the Gaels) for their faction, which controlled the Irish Free State's government. Convinced that both the Irish Free State and Northern Ireland were illegitimate, Sinn Féin declared a policy of abstentionism. Its candidates would stand for election but would refrain from entering the illegitimate parliaments if elected. This strategy ultimately failed, and votes for Sinn Féin dwindled because most Irishmen accepted the Free State and rejected as nonsensical the idea of voting for a political party that refused to participate in a legitimate government.
Sinn Féin split again in 1926 when De Valera decided to participate in parliamentary politics and left in order to found Fianna Fail. Dedicated to advancing republicanism in Ireland through constitutional means, Fianna Fail formed a government by 1932 and used its power to reconcile many republicans to normal politics. By the end of World War II, De Valera's constitutional republicanism and wartime security measures had all but destroyed the IRA and Sinn Féin.
The IRA enjoyed a brief revival after 1945, training and arming for a campaign against British interests in Northern Ireland. The offensive, known as the Border Campaign, began in 1956, and in the next year's elections, Sinn Féin won its first seats in the Dáil since 1927. The Border Campaign faltered soon thereafter and ended with a whimper in 1962.
After 1962, new leftist leaders moved the IRA and Sinn Féin toward revolutionary Marxism and away from abstentionism and military action. In December 1969, however, the IRA divided over the proper response to the outbreak of sectarian violence in Northern Ireland during the previous summer. The Provisional IRA supported armed struggle. The Official IRA, on the other hand, decided on a long-term political strategy based on Marxist theories. In January 1970, Sinn Féin split along the same lines.
The Official IRA soon repudiated military action in Northern Ireland and elsewhere, dumping its arms in 1972 and essentially dissolving as a military organization. Official Sinn Féin devoted itself to left-wing politics. In 1977 it became Sinn Féin: The Workers Party, and in 1982 it dropped "Sinn Féin" from its title.
During the 1970s, Provisional Sinn Féin (as with the IRA, the modifier soon disappeared) maintained its refusal to engage in normal politics and mainly acted as a mouthpiece for the IRA. The widespread revulsion at the deaths of republican hunger strikers in 1981 prompted republican leaders to reconsider their traditional rejection of politics. In the early 1980s, the republicans adopted a bullet and ballot box strategy. Sinn Féin became a somewhat conventional leftist political organization, while the IRA continued its military operations. In 1986, Sinn Féin's president, Gerry Adams, declared that abstentionism no longer applied to Ireland's Dáil, prompting another republican split and the consequent creation of Continuity IRA and Republican Sinn Féin.
By the early 1990s, the IRA–Sinn Féin leadership acknowledged that a military victory was unattainable. Encouraged by Sinn Féin's successes as a democratic socialist party on both sides of the border, it announced the cessation of military operations by the IRA in 1994 and, except for five months in 1997, has held to this cease-fire. The terms of the 1998 Belfast Agreement ensured Sinn Féin a place in Northern Ireland's new Assembly, effectively ending its more than seven decades in Ireland's political wilderness.
English, Richard. Armed Struggle: The History of the IRA. Oxford and New York: Oxford University Press, 2003.; Kee, Robert. The Green Flag: The Turbulent History of the Irish National Movement. New York: Delacorte, 1972.; Moloney, Ed. A Secret History of the IRA. New York: Norton, 2002.; O'Brien, Brendan. The Long War: The IRA and Sinn Fein. 2nd ed. Syracuse, NY: Syracuse University Press, 1999.