On the connection rosie17 found re travel to Boston in 1914
This is a link to a page of transcribed facts “Extracts from Report Death of American Citizen 1910-1929”It includes the reference “Michael John FINN - date of death: 1927-11-30 at Youghal, Co Cork; born 1868; Spouse's name - Mrs M FINN Manchester Green, Conn; brother - Thomas FINN resides Barry, Glam., Wales”
Civil Death Reference YOUGHAL 1927 Q4 V4 P448 age 61
Age implies he was born c1866
This record could prove useful as the name of the informant could hopefully be a relative and shed light on why he was in Ireland at that time
There is a baptism record in Youghal RC Church on Dec 13 1863
of a Michael FINN (F) Thomas (M) Johanna HEALY
(Sps) Maurice COTTER and Elizabeth COTTER
There are two further baptisms of Mary FINN 1867 and James FINN 1870
to the same parents in Youghal
Michael John FINN is listed on the 1920 US Census aged 54 at
Charter Oak Street, Manchester, Hartford, Conn., USA
with his wife Minnie and seven children
stating he was in the US since 1888
Age implies born c1866
He became naturalised in the US on Mar 27 1924 giving the same address (house #224)
certificate # 10509 US DC Hartford Conn
Locating his marriage should give a match of father’s name and following his line may be of more help