The paper presents a brief overview of the technical and market development activity undertaken by Cummins Engine Company. The process of identifying customers, demonstrating product capability to those customers, and developing the engines to meet evolving customer needs is portrayed. These activities facilitated the growth and expansion of Cummins Engine Company from a small manufacturer of single-cylinder engines for water pumping, to the largest independent diesel engine manufacturer in the world. The period of time covered is the 77 years of operation from 1919 to 1996.