Putnam took a job working for a New London, Connecticut, shipbuilding company. He left that position after a short time to become a salesman for the Package Machinery Co. of West Springfield. He rose quickly within the company's ranks, becoming president in just eight years. During the Great Depression, Putnam used his personal wealth to develop new machinery—keeping employment high. He also instituted profit sharing, gave his employees life insurance and instituted a bonus plan. Putnam was named chairman of the board at Package Machinery in 1942, where he remained until 1948.