Interesting - I have a deportee I am researching, about the same time and place.
John McGarrity was born in County Tyrone, Ireland, 1866, moved to Manchester, married Ellen McQueen in 1889 (born Lancashire to a Scottish father/Lancs mother), had 1 daughter in 1896. I have them in Lancashire in the 1891 and 1901 UK Census. John was a shop porter in 1891 and a musician in 1901. The family left England shortly after 1901 - I have mother and daughter arriving New York 13 Oct 1904. I have not found a US arrival record for John, but the family of 3 are in Pawtucket, Providence County, Rhode Island, in the 1910 US Census, and John was working as a fireman in the boiler room of the cotton mill.
April 6, 1915, John arrives Glasgow, deported, on board the Tuscania. A few days later, he is back in Lancashire and enlists in the Army. According to his pension record, John served only 43 days, before being discharged as medically unfit. His death was registered in Salford, Lancashire in the 3rd quarter of 1916.
John is possibly a first cousin of Joe McGarrity, the Tyrone-Philadelphia Clan na Gael man. If he was active in support of the Irish cause, deportation might have resulted from those actions.
This link might be useful in researching deportation
http://www.uscis.gov/history-and-genealogy/genealogy/genealogy-notebook/researching-deportation-records