My Name is Liam Horan from Ireland. I have done quite a lot of research on the Horan family both in Ireland and the U.S.
Patrick Horan and Delia Finneran arrived in Boston around 1883. The family came from county Roscommon,Ireland.
Patrick's parents were Martin and Margaret(nee Hanrahan)
Their family;Patrick 1861-1941,
James (my paternal grandfather)1864-1947
Bridget 1869 -? Unmarried
Mary Ellen 1871- ? Married Patrick Kelly.
Peter 1871-? Unmarried.
Mary Ellen's grandaughter resides in the original family home.
The Joseph Horan you refer to was,I understand adpoted by Patrick and Delia some years after the death of their own son Joseph.
Margaret Barwick's grandaughter resides in Florida, I am in regular contact with her.I understand that Margaret was the only member of Patrick and Delia's family to have childen.
I do hope that the above information will be of benefit to you.