After the war, Mackersy rejoined the bank in Vancouver. In January 1923 he was appointed an accountant in Nelson, British Columbia, and then in April 1927 an accountant in Edmonton. In August 1929 he was appointed assistant manager in Edmonton, in February 1936 assistant western superintendent in Winnipeg, and in January 1942 manager in Winnipeg. In October 1943 he was transferred to the head office in Toronto where he became general supervisor. He was appointed assistant general manager in October 1944, and general manager in January 1950. Mackersy was elected a director in 1951. In 1953, he was appointed president, succeeding Iredell Killaly Johnston, who died unexpectedly in February of that year. Mackersy remained president until 1956, when he was elected chairman of the board. In October 1960, fearful of a takeover by
Barclays Bank Canada, Mackersy opened merger discussion with Neil John McKinnon, president and chairman of the
Canadian Bank of Commerce. The first meeting happened secretively at McKinnon's house at 116 Dunvegan Road. The two men arrived quickly at an agreement, and on 1 June 1961, the banks merged to form the Canadian Imperial Bank of Commerce. Upon the merger, McKinnon became president and Mackersy became chairman. Mackersy remained in office until 23 May 1963. He remained a director until his retirement in December 1966. == Personal life ==