Sir William Christopher Macdonald was born on February 10, 1831, in Glenaladale, Prince Edward Island.

He was a Canadian tobacco manufacturer and major education philanthropist. He was educated at Central Academy in Charlottetown. As a youth, he rebelled against the authoritarian rule of his father and his Roman Catholic upbringing. At the age of 16, he renounced the church, choosing to become a non-practising Christian. At 18 he left home, making his way to the United States, where he found clerical work in Boston. Although he had limited education, Macdonald quickly showed an entrepreneurial spirit, and, joined by his brother Augustine, he organized himself as a broker to handle the shipping of American-made goods to merchants in his native Prince Edward Island. The brothers moved to the Province of Canada and settled in Montreal wherein 1858, they started McDonald Brothers and Co., a company that made tobacco products. The American Civil War opened up opportunities for export and brought them enormous financial success. About 1866 McDonald Brothers and Co. was dissolved and Macdonald was operating under his own name. He soon began using the great wealth he had earned to undertake philanthropic endeavors. He had a close relationship with John William Dawson, the principal of McGill University, and he found his life’s mission in McGill University. He practically re-founded the institution, transforming it from a medical school attached to an arts college into a full-scale university with particular strength in science. Macdonald’s gifts and bequests to McGill exceeded $13,000,000 – a sum unparalleled in Canada and other countries. A lifelong bachelor, Macdonald bequeathed his tobacco company to Walter and Howard Stewart, the two sons of company manager David Stewart. Macdonald and/or the Macdonald Stewart Foundation funded several McGill University facilities, e.g., Macdonald Campus, Macdonald Engineering Building, Macdonald-Harrington Building, and Macdonald-Stewart Library Building.

He died on June 9, 1917, in Montreal, Quebec.