Johnson became vice president at J&J in 1918. Johnson also had an abiding interest in politics, and served a term as the mayor of Highland Park, New Jersey from 1920 to 1922. He was elected president of Johnson & Johnson from 1932–1938, and became chairman of the board of J&J in 1938. Johnson also held a reserve commission in the U.S. Army Quartermaster Corps during the 1930s. At the outbreak of World War II, Johnson's work in identifying products needed by the war effort resulted in the Permacell division of J&J inventing duct tape for sealing ammunition boxes. J&J plant managers simply took their existing cloth medical adhesive tape, added a waterproof plastic layer with a more aggressive adhesive, and produced it in olive drab (OD) green to match the ammunition cans. During the war, J&J would become a major supplier for combat first aid kits and other military supplies. In 1941, Johnson started the Ethicon subsidiary.