A little bitt more on George. He looks to have travelled to the US onboard the Columbia that arrived 31st May 1908, albeit for some reason his name and details are scored through on the arrival records and indeed some details aren't even recorded, so perhaps he didn't complete the journey on that occasion. His name, with no score through, is on the departure list of 23rd May from Londonderry though.
Nellie Irvine arrived on 16th December 1908, and the passenger arrival record noted she was travelling to her friend, George Lillie, at the Globe Hotel, Cedar Rapids, and that her nearest friend/relative in country of departure was her mother, Jane Irvine, of Skegoneill Avenue, Belfast (so this 1901 census entry
http://www.census.nationalarchives.ie/pages/1901/Antrim/Duncairn_Ward/Skegoneil_Avenue/1005028/ albeit as Irwin) . This ties in well with the marriage record entry aghadowey linked to, showing a marriage on 18th December at Cedar Rapids.