What did Watson and Crick; Rosalind Franklin; Avery, MacLeod, and McCarty; and Hershey and Chase do?

A brief rundown:

Watson and Crick — proposed double helix structure of DNA in 1953.

Rosalind Franklin — carried out X-ray crystallography analysis of DNA that was shared by Maurice Wilkins with Watson and Crick, who recognized the images to show a double helix.

Avery, MacLeod, and McCarty — published a paper in 1944 saying that Griffith's "transformation factor" was DNA, not protein. They found that DNA was the agent that carried genetic charcteristics from one generation to the next.

Hershey and Chase — carried out experiments that lent strong support to the theory that DNA is the genetic material.