Moffatt McDonald received an A.B. from Erskine College and an LL.B. from the University of South Carolina. He was married to Miss Rachel Boyce of Due West, South Carolina. He practiced in Columbia from 1913 until 1923 and then in Greenwood until his death in 1953. He was also awarded an LL.D. by Erskine College.He was from a family of able lawyers. His father, J.E. Mcdonald, an eminent lawyer at Winnsboro, had three sons and three grandsons, all worthy representatives of the South Carolina Bar.
His major interest at the Bar lay in the advancement of transportation, industrial and commercial interests of his county and state. It was written of him that, “As a lawyer he had few peers, a brilliant intellect and a keen analytical mind.”
He had wide interests outside his profession. He served as a Trustee of the Greenwood School from 1933 until 1953, as an Elder of the Associate Reformed Presbyterian Church at the time of his death, and as the teacher of the Men’s Bible Class which now bears his name.