The Thomas Mc Donald Family of Illinois

I'm researching my family that started in Canada with the birth of my great grandfather Daniel Oct. 8,1888 and his wife Margaret Keating born June 12, 1895 in Canada. When Dan immagrated his name may have been changed to McDonald, no one is sure what it was before, or if it really was changed. We think he was born in Montreal and Margaret was born in Nova Scotia. They had two sons Daniel and Thomas. I'm still looking into where they were born. Thomas, my grandfather was born on March 29, 1919. He married Helen Forni I think in Dec of 1942. They had two children Thomas Harris Jr. Nov 12, 1943 and Mary Ann Born Nov 28, 1945 or 46 ???? My father Thomas Jr. Married Rose Hill Sept 15, 1962 and had three children Donna Marie (me) March 16, 1963. Elisabeth Rose Aug. 31, 1966 and Thomas III Jan 21, 1970. Any information about this family tree and any of its branches would be greatly appriceated.