Thomas James "Tom" Clarke was born March 11, 1858, probably in Hurst Castle, Hampshire, England. The eldest child of James (1830-), a bombardier in the Royal Artillery from County Leitrim, and Mary Palmer of County Tipperary, the family moved to South Africa the following year for James Clarke's military career. In 1867 the family moved to Dungannon in County Tyrone, Ireland, where James Clarke quit the army in 1868. Tom Clarke was educated at St. Patrick's National School in Dungannon.

Tom Clarke emigrated to New York in 1880, where he was employed as a hotel porter and attended bomb-making classes taught by Thomas Gallagher (1851-1925). In 1883 he went to England on a bombing mission and was caught and arrested with Gallagher in April. In June that same year he was convicted of treason and sentenced to penal servitude for life.

Throughout his imprisonment, which lasted until fall 1898 when Amnesty Association requests for release were successful, Clarke used a pseudonym, "Henry Hammond Wilson." He was mostly held at Chatham Prison, which was known for its cruel treatment of felons convicted of treason. Clarke survived this sentence, and his experiences were published in Irish Freedom in 1912 and posthumously in the volume Glimpses of an Irish Felon's Prison Life (1922).

Clarke remained committed to the Irish Fenian cause after his release. Finding it difficult to find work in Ireland, he emigrated again to the United States in 1900. There he was employed as a metalworker, clerked for Clan na Gael, acted as John Devoy's private secretary, and helped launch and served as assistant editor for the Gaelic American newspaper. Tom Clarke married Kathleen Daly, the niece of John Daly, in 1901, with whom he had three children. He became a naturalized U.S. citizen in 1905.

Clarke returned to Ireland in late 1907 and found younger Irish Republican Brotherhood (IRB) members revered him for his dedication to the nationalist cause. He helped militants gain control of the IRB, joined the Gaelic League and Sinn Féin, and published Irish Freedom from 1910 until its suppression in 1914.

With the onset of World War I, Clarke was one of the main instigators of the 1916 Easter Rising. He was relieved when, after the surrender, he was sentenced to death and would not have to endure prison again. He was shot at Kilmainham Jail on May 3, 1916, and buried at Arbour Hill prison cemetery.

[Information retrieved from Quinn, James, "Clarke, Thomas James ('Tom')," Dictionary of Irish Biography.]

Seán McGarry was the son of John and Mary (Kelly) McGarry, born in Dundrum, County Dublin, Ireland. He worked with Bulmer Hobson and Denis McCullough in the early 20th century to revive the Irish Republican Brotherhood (IRB), managing the Belfast-based paper the Republic and helping found the Irish Volunteers in 1913.

McGarry was on headquarters staff during the 1916 Easter Uprising. Initially sentenced to death, his sentence was commuted to penal servitude for 8 years, but he was released in the June 1917 amnesty.

After the death of Thomas Ashe in fall 1917, on hunger strike in prison, McGarry was named president of the IRB supreme council. Arrested again in May 1918, McGarry escaped with Éamon de Valera and Sean Milroy on February 3, 1919.

McGarry was first a councillor and then an alderman on the Dublin Corporation from 1920-1924. In support of the Anglo-Irish treaty, he was targeted during the civil war by those against the treaty. His home was burned in an Irish Republican Army (IRA) raid in December 1922, his son Emmet killed in the fire.

McGarry was elected Teachta Dála (TD) for Dublin North but resigned from his seat in 1924 in protest for the way the 1924 army mutiny was handled by the government. Retiring from public life, he thereafter wrote articles, engaged in radio broadcasting, and was employed by the Irish Hospitals Trust. Seán McGarry died in 1958 of a heart attack.

[Information retrieved from White, Lawrence William, "McGarry, Seán," Dictionary of Irish Biography.]