Listed on the National Register of Historic Places in 1977, the Lilly Biological Laboratories in Greenfield, Indiana, stands as a highly significant monument to the evolution of the American pharmaceutical industry. Established in 1913 by Eli Lilly and Company, this sprawling campus was designed to isolate the delicate and highly sensitive production of biological medicines-such as vaccines and antitoxins-from the urban pollution of the company's downtown Indianapolis headquarters. The rural Hancock County site provided a controlled, sanitary environment where scientists and technicians could cultivate the animal serums required for early twentieth-century immunology, making it one of the earliest and most advanced industrial biological research and manufacturing facilities in the United States.

The historical significance of the laboratories lies in their profound contribution to global public health and medical science. It was at this facility that Eli Lilly and Company successfully standardized and mass-produced vital treatments, including diphtheria and tetanus antitoxins, smallpox vaccines, and later, the world's first commercially viable mass-produced insulin in the 1920s, which saved the lives of millions of diabetics worldwide. The campus reflects the critical transition of pharmacy from small-scale, empirical compounding to modern, scientifically rigorously controlled mass production, symbolizing a golden age of medical innovation and industrial research that reshaped twentieth-century healthcare.