After the war, he took a job for W.R. Grace and Company. Douglas Campbell began work in April 1919 in New York. Two years later he arrived at the Hacienda Cartavio in Peru where he worked as an accountant. Cartavio was a farm where sugarcane is grown and where W. R. Grace & Co. had built the first mill to produce sugar at the end of the nineteenth century. He worked for about eleven years there. After he became the Vice-President of Pan-American Airways in 1939 and was named the airline's general manager in 1948. He died in Greenwich, Connecticut at the age of 94.