Donald Carmichael Sinclair, QC, only child of John H. Sinclair and Jessie (Carmichael), was born in 1888 at New Glasgow, N.S. He attended Dalhousie University where he obtained a degree in arts followed by an LLB in 1909. After a few years in the law office of Hector MacInnis, Sinclair returned to New Glasgow where he practiced with his father. Later he became a partner with D.D. Macdonald. In 1915 he married Norma MacKay of New Glasgow, daughter of Norman and Ann (Hunter) MacKay. They had three children: Janet, John and Norman. Sinclair served with the military in both World Wars and became an honourary colonel of the Pictou Highlanders. He was also a member of several political and community organizations. He sat on the first Regional Library Board for Pictou County, was president of the Nova Scotia Liberal Association, and held many offices for the Pictou County Liberal Association. Sinclair was a stipendiary magistrate for New Glasgow and held directorships of local companies such as Eastern Trust Co. and Eastern Light and Power Company Ltd. He was also associated with the family firm founded by his grandfather, J.W. Carmichael and Co. Ltd., and was president of the firm at the time of his death on 24 March 1962.