 Burkhardt held his first solo exhibition in 1939 at Stendahl Gallery in Los Angeles, arranged by Lorser Feitelson, and, in response to the Spanish Civil War, he painted his first anti-war works.From the late 1930s he began to produce apocalyptic anti-war compositions, a theme which became particularly pronounced in an abstract expressionist style after the atom bomb was dropped on Hiroshima and Nagasaki at the end of the Second World War.He was praised for his “willingness to confront political reality directly in his art,” and in the 1940s he embarked on a body of work that underscored the duality evident throughout his entire oeuvre—cathartic works of power and poignancy contrasted by works of celebration and hope.