Alfred Hershey teaches at the Department of Bacteriology of the Washington University School of Medicine. There, he starts working on bacteriophage along with Jacques Jacob Bronfenbrenner, a pioneer in the field of bacteriophage research. From 1936 to 1939, Hershey and Bronfenbrenner publish several papers on the growth of bacterial cultures. Hershey is promoted to Instructor (1936), Assistant Professor (1938), and Associate Professor (1942).

Alfred Hershey receives one third of the Nobel prize in Physiology or Medicine along with Max Delbrück and Salvador E. Luria "for their discoveries concerning the replication mechanism and the genetic structure of viruses".

Alfred Hershey becomes Staff Member at the Department of Genetics, Carnegie Institution of Washington, Cold Spring Harbor.

Together with his assistant Martha Chase, Alfred Hershey conducts the Hershey-Chase experiment showing that phage DNA is the principal component entering the host cell during infection. Hershey proves that DNA, rather than protein, is the genetic material of the phage. Hershey's discoveries provide crucial input to Francis Crick and James Watson in their subsequent unraveling of DNA's double-helix structure.

Alfred Hershey attends Owosso High School.

Alfred Hershey enters Michigan State University. Here he earns his BS in chemistry.

Alfred Hershey is appointed Director of the Genetics Research Unit at the Carnegie Institution of Washington, Cold Spring Harbor. He leads research projects on bacteriophage, focusing on phage recombination and genetics. In 1974, Hershey retires, though he visits regularly Cold Spring Harbor Laboratory.

Hershey starts visiting Delbrück, the leader of the Phage Group, a team of biologists working on bacterial genetics and molecular biology. “Phage” derives from bacteriophages, viruses that destroy bacteria. The Phage Groupe uses them to study self-replication, mutation, and other life processes. Thanks to Delbrück's finding, Hershey notices that viruses infecting the same cell show an unexpected interaction. He proves that this is the result of genetic recombination and that could be used to map the genes of viruses.

Alfred Hershey earns his Ph.D. in bactereology at Michigan State University. His thesis inspects the chemistry of Brucella bacteria, the bacteria responsible for brucellosis, also known as undulant fever.

Alfred Hershey dies of cardiopulmonary failure at the age of 88 in Syosset, NY.

Alfred Hershey is born in Owosso to Robert Day Hershey, an employee in an auto manufacturing firm, and his wife, Alma Wilbur Hershey.