Thomas D'Arcy McGee was born in Carlingford, Ireland April 13, 1825. He was the fifth child of James McGee and Dorcas Catherine Morgan. He received his early education in County Wexford, Ireland. In 1842 he moved to the U.S. He stayed briefly with an aunt in Rhode Island, and then moved to Boston where he edited the newspaper The Pilot. In 1845 he returned to Ireland and edited the Irish nationalist paper Nation. In Ireland, McGee was linked to the Rebellion of 1848 and was forced to flee to the U.S. For the next nine years he edited newspapers. He founded and edited the New York Nation (1848-1850). McGee then founded the American Celt which he based successively in Boston (1850), Buffalo (1852), and New York (1853). In the spring of 1857 he was invited to Montreal by prominent members of the Irish Catholic community. He moved to Montreal in 1857 and for two years edited the paper New Era (1857-1858). He studied law at McGill University, graduating in 1861.
McGee's political thought was influenced by his experience with the Irish nationalists' cause. McGee called for a new nationality in Canada, which meant the federation of British North America, a transcontinental railway, settlement in the West, and a distinctive literature. In November of 1858 at a St. Patrick's Society meeting McGee was nominated to represent the riding of Montreal West in the upcoming election. McGee won. McGee allied himself with George Brown's Reform party. When Brown's government failed in the elections of 1861, McGee shifted his alliance toward the Conservatives.
D'Arcy McGee was married to Mary Theresa Caffrey in Ireland on July 13, 1847. The couple had five daughters - Martha Dorcas, Euphrasia (Fasa), Rose, Agnes (Peggy), a fifth (name unknown), and one son, Thomas Patrick Bede. Only Agnes and Euphrasia outlived their father. Thomas D'Arcy McGee was assassinated April 7, 1868.