A gifted athlete, Buchanan was a pitcher on the 1936 St. Croixs baseball team that won the New Brunswick Senior Baseball League Championship and the Maritime Senior Baseball Championship. He worked in the family's retail furniture business until the oubreak of World War II. He served overseas in the Royal Canadian Army, rising to the rank of Major. He was awarded the Military Cross with two bars for acts of exemplary gallantry during active operations against the enemy on land. In 1944 he married Janet C. Wilson. Their first child, a daughter Janice, was born in 1945 in Irving, Ayrshire, Scotland.