Hallam’s paintings often depict simple scenes, showing harbours in Nova Scotia, farms in Quebec, sideroads in Ontario, people swimming beneath small falls, churches, lakes, and autumn woods.

Hallam sketched often with artists as he worked at Sampson-Matthews. His work was reproduced by the firm in 1943 as part of the National Gallery’s plan to furnish scenes of Canada for the Canadian armed forces throughout the world. Also a teacher at Ontario College of Art, he taught figure drawing from 1940-45.

Hallam exhibited widely; in the 1930s at the Canadian National Exhibition; a solo show at the Laing Galleries in Toronto in 1951; Roberts Gallery in 1958 and at the Art Gallery of Windsor in 1961.

His work is held in numerous public collections, including The National Gallery of Canada, the collection of Her Majesty Queen Elizabeth II, the collection of the late Pope Pius XII, the Art Gallery of Ontario and the Public Library and Art Museum of London, Ontario.