The pathologist Harold Lindsay Amoss was born in Cobb, Kentucky, on September 8, 1886. After receiving his BS (1905) and MS (1907) degrees at the University of Kentucky, he pursued both medical degree and doctorate at Harvard, receiving them in successive years, 1911 and 1912.

Amoss's early career was marked by an atypical academic vagabondage that saw him shift positions nearly every year. He passed through jobs with the Kentucky Agricultural Station (1905-1906), the Hygienic Laboratory of the U.S. Public Health Service (1906-1907), and the Bureau of Chemistry of the U.S. Department of Agriculture (1907-1908) before landing a position in the Harvard Medical School. In 1912, he was lured to the vibrant life at the Rockefeller Institute to work in pathology and bacteriology. Interrupted by service in France during the First World War, Amoss' research was focused on a variety of infectious diseases, including poliomyelitis, meningitis, erysipelas, brucellosis, and encephalitis and on the development of vaccines.

Leaving the Rockefeller in 1922, Amoss joined the Johns Hopkins School of Medicine (1922-1930) as a professor of medicine and worked briefly at Duke University (1930-1933), before returning to the Rockefeller in 1933 as a medical consultant. He remained associated with the Rockefeller.