In 1942, Earl volunteered for a job in the Navy but failed to pass the physical examination. Instead, he participated in a wartime project of mapping a route in Alaska known as the Alaskan-Canadian (Al-Can) Highway. Upon the completion of this survey in 1943, Earl returned to Berkeley and paid a visit to Horace A. Barker, for whom he had worked as a laboratory technician. Barker was at that time directing various war efforts in the department of food technology. Earl accepted an offer to work as principal investigator on a project studying the "Browning of Dried Apricots," the goal of which was to find a way of preventing dried fruits from deteriorating rapidly in the high temperatures of the South Pacific. It was a rewarding experience for him, since he was directly involved in research for the first time in his life and learned to use various experimental tools, including analytical spectroscopy, colorimetry, ion-exchange methodology, and column and paper chromatography.

Earl in Alaska

Earl's award from the Al-Can Highway Project

In 1943, Thressa Campbell enrolled as a graduate student at the University of California, Berkeley. By that time, programs at the Berkeley campus had been reoriented toward various wartime projects, and many courses had been suspended. Thressa accepted a position as a laboratory assistant in the food technology department, working on the stability of foods to be shipped to soldiers in the South Pacific.

Thressa and Earl first met in 1943 at Berkeley and married later that year. After the war, Thressa and Earl both started graduate studies in the Department of Biochemistry, working with the same mentor, Horace A. Barker. They completed their doctoral studies in 1949 and moved to the East Coast for their postdoctoral training. Earl worked in Fritz Lipmann's laboratory at the Massachusetts General Hospital as an Atomic Energy Commission Fellow. Thressa secured a position as a research assistant in Christian Anfinsen's laboratory at Harvard Medical School.

Thressa and Earl at their graduation, 1949