Author, biographer, and historian. "Mack did extensive archival research in France, England and the United States on Paul Cézanne before publishing a highly praised biography of the painter in 1935. He followed this with a biography of Henri de Toulouse-Lautrec in 1938, which was equally well received. During World War II, Mack served in the military in England with the Office of Strategic Services. The Land Divided, his history of the Panama Canal, was published in 1944 and his biography of Gustave Courbet appeared in 1951. In 1981, he wrote a book on the 1906 San Francisco earthquake and fire, which he personally survived. Manhattan has been Mack’s home since 1938, but he travelled extensively across the world." - Google Books bio Source: OpenLibrary