The Macmillan Company, which was incorporated in 1896 as a successor to Macmillan & Company [no publs. in LC data base], merged with Crowell-Collier Publishing Company, in 1960 and became a subsidiary. Both names continued in use until 1965 when the name of the Crowell-Collier Publishing Company was changed to Crowell, Collier and Macmillan. In 1973 the name of Crowell, Collier and Macmillan was changed to Macmillan, inc., and the name of the subsidiary Macmillan Company was changed to Macmillan Publishing Company.

Cyrus John MacMillan was born on September 12, 1878, in Wood Islands, Prince Edward Island and died on June 29, 1953. In Montreal in 1916, he married Margaret Eaton Brower, who attended McGill University. They had no children. MacMillan earned his B.A. in 1900 and his M.A. in 1903 from McGill. After receiving his Ph.D. from Harvard in 1909, he returned to McGill as a Lecturer in English. MacMillan served in the First World War with the 6th and 7th Canadian Siege Battery, which he helped to organize. In 1919, he was promoted to Associate Professor and was appointed Chair of the English Department in 1923. From 1940 to 1947, he was Dean of the Faculty of Arts and Science. During this period, MacMillan pursued a second career as a politician. He was the Federal Minister of Fisheries in 1930, and federal M.P. for Queen's (P.E.I.) from 1940 to 1945. From 1943 to 1946, MacMillan was the Parliamentary Assistant to the Minister of National Defence for Air and served on numerous government committees. MacMillan was a member of the Presbyterian Church of Canada and served as the sole lay delegate to the Church of Scotland assembly in Edinburgh. He also published a book about the history of McGill called McGill and Its Story, 1821-1921, as well as volumes of Canadian folktales and studies of Canadian literature. After 1945 he was chief editorial writer for the Charlottetown Patriot, until his retirement in 1947.

Hugh Pattison Macmillan, Baron Macmillan, was born on February 20, 1873, in Glasgow, Scotland.

He was a Scottish advocate, judge, parliamentarian, and civil servant. He was educated at Collegiate School, Greenock (1878), Edinburgh University (M.A., 1893), and Glasgow University (LL.B, 1896). He was admitted to the Faculty of Advocates in 1897 and became King's Counsel in 1912. He wrote articles on conveyancing for Green's Encyclopedia of Scots Law and was editor of the quarterly Juridical Review between 1900 and 1907. During the First World War, Macmillan served as Assistant Director of Intelligence for the Ministry of Information. In 1923, he was elected a Fellow of the Royal Society of Edinburgh. He was sworn to the Privy Council in April 1924 and served as Lord Advocate from February to November 1924. In London, Macmillan enjoyed a varied practice in the House of Lords and the Privy Council, as well as before parliamentary committees. He was appointed standing counsel for Canada (1928) and Australia (1929). In 1930, Macmillan was made a Lord of Appeal in Ordinary with the customary life peerage as Baron Macmillan of Aberfeldy in the County of Perth, a post he held until 1947. He held several chairmanships, including the Committee on Finance and Industry (1929–1931), the Canadian Royal Commission on Banking and Currency (1933), the Pilgrim Trust (1935-1952), the Political Honours Committee (1935-1952), the Court of the University of London (1929-1943), and the BBC Advisory Council (1936-1946). He was elected Trustee of the British Museum and was a principal proponent and founder of the Stair Society in 1934. Macmillan received an honorary degree of LL.D. from Edinburgh, London, St. Andrews, McGill, Queens, Dalhousie, and Columbia universities. In 1924, he was elected the first Honorary Bencher of Inner Temple and was awarded the Royal Victorian Order in 1937.

In 1901, he married Elizabeth Katherine Grace Marshall (1873–1967). He died on September 5, 1952, in Ewhurst, Surrey, England.