Since 1930, Hamilton Standard (now Hamilton Sundstrand) was involved with revolutionizing the propulsion technology of propeller-driven aircraft, prior to World War II. The introduction of Frank Caldwell's variable-pitch propeller made Hamilton Standard one of the leading aerospace companies of today. Hamilton contributed a great deal in shaping the aviation industry into what it is today. Hamilton worked hard from an early age to understand technical concepts and their application to aircraft design and manufacturing. He was also a skilled businessman and marketer, known in social and political settings, and a devoted family man.