If this were my research, I would search the Tithe A for Co. Monaghan. http://titheapplotmentbooks.nationalarchives.ie/ For example there are 'only' 297 Kelly families listed at that time. I searched on Owen Kelly. In one townland there are Owen, Jas, Luke, and Philip in Drumacrew, Clontibret. Think Philip is unusual, as is William for a Catholic family. Search on Welsh also. There are only 47 of that names. Could be Walsh - only 55. Look at other names in the townland. Back to the ship's lists and see if there are others of names in the townland - or nearby. Yes, young children did sail w/o parents - perhaps relatives or neighbors. On his citizenship papers - or petition for citizenship, who were his sponsors? That is often a clue. There were emigration agents in cities in the US. Someone in the US could have purchased a ticket for him. Not sure that any of those records are about. In Rhode Island, US Army agents went to Ireland to hire workers for Fort Adams, 1824 and continued at irregular intervals until 1857. There may have been other similar events, i.e. for the canals in the US and Canada. Someone may have come for work, and brought along young Owen. He was almost working age!!! Many wounded from the US Civil War had pensions. That is also a resource. A widow would petition after her husband's death. I have a Kelly from Co. Monaghan who came to RI in the early 1850'ties. Mary Kelly, father Peter(?) married Patrick Connolly of Clontibret. Hard with both names!! Lots for a rainy day searching! Regards, Ann