Hello Slip, you almost slpped by me as I was notified of your post among some others and Leitrim always take my interest. John MCTague born in Balbriggan and and baptised on 10th February 1847 but the father is Michael and mother is Jane Grimes, the witnesses are Richard Markey and Ann Connelly, There are siblings including twins of this marriage although the mother is always Grimes there are two differetn Christian names used. I see a Grimes marriage in Dublin city of a Hugh in 1831, there is a Patrick marriage in Leitrim and else where also two in Letrim one in 1846 and a possible in in 1834 but the name is Tighue or commonly Tighe I would think.
Balbriggan was famous at the time for wool garments and people there were activly recruited to work in the US, travel was often via Canada as it was in the then British Empire and so cheaper travel was available and people then went to the US, also the gold mines in Bute were a big draw for people especially from the Roscommon Leitrim area, I think the owner of the biggest mine was from Roscommon and people went from the area, also from a documentary I saw he set up schools etc for the children, ran the place by looking after the staff of families as there was high mortality among the workers, silica dust I think.
I see one McTague here on a Leitrim site https://www.yourleitrimancestors.ie/ and there are a few mentions on the Facebook Leitrim History page and one on the South Leitrim Gedmatch page.
There is no birth of a John to father Patrick 1840 to 1860 on the available baptismal records.
If you find some more information start a new thead as it will be seen by those volunteers who are active while on the few of us on here get notified.
Good Luck
Pat