Found a Michael MURDOCK in the Ohio 1850 census - Mahoning Co, Youngstown, pg 15/16
Michael Murdock, 32, m,w,laborer, b. Ireland
Elizabeth27, f,w,b. NY
Anna6/12 f,w,b. Ohio
Bridget32 f,w,b. Ireland
Martin16, m,w,b. Ireland
Mary14, f,w,b. Ireland
Ba??ba10, f,w,b. Canada
Thomas8, m,w,b. Canada
Patrick5, m,w,b. Canada
The place is correct from my records as well as Mary's age and place of birth.
My 'guess' is that Bridget was the wife of one of Michael's brothers and Martin and Mary were Michael's brother and sister.Michael may have emigrated through Canada>NY to Ohio.
I have Michael's descendants through the McGEE line to the present.Am most willing to share information.