Looking for any or all information on my following ancesters. Archibald Stewart b. abt. 1750 in Ireland Father of Christopher Stewart. Did he immigrate to Pa.?

Christopher Stewart 1775-1864 m. Barbara Deemer 1772-1859.
Lived in Westmoreland Co. Pa.. Moved family to Donegal Twp. Butler Co. Pa. in 1797. Children inter-married with the Barnharts and Hemphills in Donegal Twp. Pa..
My line comes down through Chistopher, John and Adam Stewart.