[7][6] Shortly before the start of the First World War, Cowie was appointed art master at Bellshill Academy near Glasgow.
During the war he registered as a conscientious objector and, after appearing before the Glasgow Military Service Tribunal, he agreed to serve in the Non-Combatant Corps.
During this time he continued to paint, often producing portraits of his students based on detailed preparatory sketches done in pencil or watercolour.
[9] Cowie held his first solo exhibition at the McLellan Galleries in Glasgow in 1935 and the same year he took the post of Head of Painting at Gray's School of Art.
[2] In October 1941 Cowie was commissioned by the War Artists' Advisory Committee to produce a portrait of a Scottish Civil Defence worker.