Looking for my Grandfather John W Hagan born circa 1985 +/- 4 years

Looking for my Grandfather John W Hagan

My name is Debbie, I am originally from Fall River, Bristol County, Massachusetts, but now live in Rhode Island in the US. 

I am looking for information on my grandfather John William Hagan born 31 May 1894 -1896 depending on the record (he is my mother's father) most likely born in Belfast, again depending on the record. So far I've not really been able to narrow him down to a county in Ireland so I am hoping someone will see this who can help me.

John William Hagan said he came here to the US thru New York, New York, the USA around 1908-1910. I'll try to make this concise so these are the only records I can find for John:

1917- Marriage Certificate to Eliza Royds, in Newport, Newport County, Rhode Island, USA  on 17 May 1917, his DOB 31 May 1895 in Ireland, parents John William Hagan and Jennie Russell Both born Ireland.

1917- U.S. WW1 Draft Card: DOB- 31 May 1894, born in  Dublin, Ireland.

1918- Canada Attestation Papers- WW1 C.E.F. DOB 31 May 1896, born in Belfast, Ireland; Roman Catholic.

May 1919- U.S., Records of Aliens Pre-Examined in Montreal Canada: (born in Belfast, Ireland, arrived NY, NY around 1910) 

June 1919- Border Crossings: From Canada to U.S., 23yrs, born in Belfast, Ireland went thru Vermont, USA to go back to Fall River, Bristol Co., MA, USA.

1920 Census- in Fall River, Bristol Co., MA, USA; birth around 1896, born in Ireland; Father and Mother both born in Ireland

1930 Census-:  in Fall River, Bristol Co., MA, USA; birth around 1895, born in Irish Free State, Father in Irish Free State and Mother born in Scotland.

After about 1945 or so he left my grandmother  in Fall River, Bristol Co., MA, USA (after 16 children) and no one knew where he went or when he died,

ANY help at all will be appreciated, Thank you for listening 

Debbie Valentine (divalentine57@verizon.net)