The people who built Cummins: Clessie and the War

On December 7, 1941, the attack on Pearl Harbor launched the United States into the fray of World War II. Overnight, all of Cummins’ production was devoted to the war effort.  

Clessie was called upon by the United States Government to join the War Production Board in the Automotive Division to represent the interests of the diesel industry. Clessie worked tirelessly throughout the war, traveling back and forth between Columbus and Washington, D.C., to fulfill his duties to the company and his country. In the early years of the war, the U.S. Government believed it was more cost-effective to use gas engines for land vehicles such as tanks, so Cummins mostly provided generator sets for naval ships and the Signal Corps. Eventually, the U.S. Government warmed to the idea of diesel for heavy-duty trucks, likely due to Clessie’s involvement on the War Production Board. Cummins was charged with producing engines for a variety of heavy-duty machinery for the Army. By the end of the war, Cummins had produced over 4,500 HB600 engines for the Army as well as Model A and Model K generator sets. Throughout the war, Cummins received three Army-Navy “E” Awards honoring its service: the first on January 28, 1943, the second on March 10, 1944, and the last on July 17, 1945.

Clessie’s health had been in rapid decline since before the War. So, after victory was declared in Europe, Clessie decided he wanted to move somewhere sunnier without the harsh Winters of the Midwest. In July 1945, he moved to Sausalito, California, along with his wife and three of their children. Despite Clessie’s geographic location, the Company’s executives felt it needed to remain linked to Clessie’s name and urged Clessie to stay on as the Company’s president. In 1947, J. Irwin Miller took over as president, on the condition that Clessie become the chairman of the board. Clessie remained so until 1951, when he completely retired from the Company. Clessie spent his retirement inventing and innovating in his personal workshop in California. It was during this time that he designed many of his most important inventions.