[3] He emigrated to the United States at fifteen years of age and with his brothers, John and Mortimer, settled in Chicago.
Scanlan joined the Irish Republican Brotherhood (IRB) and wrote articles and poems for a number of newspapers.
[1] He edited the Irish Republic, described in its masthead as a "journal of liberty, literature, and social progress",[2] together with Patrick William Dunne and fellow IRB exile David Bell.
[6] In the Irish Republic, Scanlon and Bell promoted physical-force Fenianism, while disparaging the general clericalism and pro-Democratic-Party leanings of rival Irish-American papers.
[7] The Irish Republic supported the Radical Republican agenda for Reconstruction, black suffrage and equal rights.