John Hamilton Bush (1909–1977), primarily known as Jack Bush, was a Canadian painter best known for his Abstract Expressionist style. Born in Toronto, he lived in London, Ont. and Montreal during his early years. Jack Bush began his career in advertising, working in his father’s firm, Rapid Electro Type Company in Montreal. During this time, he studied at the Art Association of Montreal with Edmund Dyonnet and Adam Sherriff Scott. In 1928, he transferred to the company’s office in Toronto, where he took evening classes under Frederick Challener, John Alfsen and Charles Comfort at the Ontario College of Art. Bush’s early work as a painter was influenced by Comfort and the Group of Seven, and throughout the 1930s and ‘40s he produced largely landscape and figurative paintings. His first exhibition was with the Ontario Society of Artists in Toronto in 1936.In 1934, Jack Bush married Mabel Mills Teakle, a family friend from Montreal, and together they had three sons, Jack Jr (b. 1936), Robert (b. 1938) and Terry (b. 1942). In 1953, dissatisfied with Canada’s place in the international contemporary art scene, Bush and several other Toronto abstract artists founded the group Painters Eleven. William Ronald, another member of Painters Eleven, and an artist who had worked in New York, introduced U.S. art critic Clement Greenberg to the group, which led to a lasting friendship between Bush and Greenberg. The contact with Greenberg in 1957 led to Bush’s international breakthrough in the early 1960s, beginning with his 1962 exhibition at the Robert Elkon Gallery in New York. Between the late 1950s and mid ‘60s, Bush painted in loose brushstrokes with diluted oils, staining paint onto unprimed canvas. In 1966, concerned by the health hazards associated with oil-based paints, he switched to water-based acrylics, less textured than oils but more brightly coloured.In 1964, Jack Bush’s work was included in Greenberg’s Post-Painterly Abstraction at the Los Angeles County Museum, an exhibition that travelled to Minneapolis and Toronto. Along with Jacques Hurtubise, Bush represented Canada at the Bienal de São Paulo (Brazil) in 1967. In the year preceding his death in 1977 (from a heart attack), he received the Order of Canada. That same year, the Art Gallery of Ontario mounted a retrospective exhibition of his abstract works that travelled to several Canadian galleries. Jack Bush’s work is in the collections of the Art Gallery of Ontario, the National Gallery of Canada, the Montreal Museum of Fine Arts, Boston’s Museum of Fine Arts, London’s Tate Gallery and others.