I was born on September 29, 1931 in Chicago, Illinois, while my father, James Farley Cronin, was a graduate student at the University of Chicago. He was a student of classical languages. My mother, Dorothy Watson, had met my father in a Greek class at Northwestern University. After a brief stay at a small school in Alabama, my father became Professor of Latin and Greek at Southern Methodist University in Dallas, Texas, in September 1939. My primary and secondary education was provided by the Highland Park Public School System. I received my undergraduate degree from Southern Methodist University with a major in physics and mathematics in 1951. In high school my natural interest in science was encouraged by an excellent physics teacher, Mr. Charles H. Marshall. He stressed analytical methods as applied to simple physical systems as well as practical experimental problems.

My real education began when I entered the University of Chicago in September 1951 as a graduate student. I was fortunate to have among my classroom teachers, Enrico Fermi, Maria Mayer, Edward Teller, Gregor Wentzel, Val Telegdi, Marvin Goldberger and Murray Gell-Mann. I did a thesis in experimental nuclear physics under the direction of Samuel K. Allison. While at Chicago my interest in the new field of particle physics was stimulated by a course given by Gell- Mann, who was developing his ideas about Strangeness at the time.

It was also at the University of Chicago that I met my future wife, Annette Martin, in the summer of 1953. It was a wonderful, happy summer; I had passed my Ph.D. qualifying exams the previous winter, and I realized that I had met my lifetime companion. We were married in September 1954. The stable point in my life became our home. On even the worst days, when nothing was working at the lab, I knew that at home I would find warmth, peace, companionship, and encouragement. As a consequence, the next day would surely be better. Annette, with great patience and good spirit, tolerated my many long absences when experiments were carried out at distant laboratories.

After receiving my Ph.D. in 1955 I had the opportunity to join the group of Rodney Cool and Oreste Piccioni who were working at the Brookhaven Cosmotron, a newly completed 3 GeV accelerator. That period was an exciting time in physics. The famous tau-teta puzzle led to the prediction of parity violation and the experimental demonstration of its violation. The long-lived K meson was discovered at Brookhaven.

When the violation of parity was discovered I began a series of electronic experiments to investigate parity violation in hyperon decays. In early 1958 the Cosmotron suffered a severe magnet failure. As a consequence, we moved our experiment to the Berkeley Bevatron. Here I had the good fortune to meet William Wenzel and Bruce Cork. These physicists had a great influence on me. From their example I learned not to be intimidated by complex pieces of apparatus.

While at Brookhaven I met Val Fitch who was responsible for my coming to Princeton University in the fall of 1958. At Princeton all the work in particle physics was supported through a contract with the Office of Naval Research. The Director of the Laboratory, George Reynolds, was most supportive of my efforts to work independently. There followed for ten years a glorious time for research. I was much involved in the development of the spark chamber as a practical research tool. During this period, with a series of excellent students, we further studied hyperon decays. Then we joined with Val Fitch to study neutral K meson decays which led to the discovery of CP violation.

Following the discovery in the summer of 1964, I spent a year in France working at the Centre d’Etudes Nucleaires at Saclay with Rene Turlay. In addition to the research, I enjoyed learning French and assimilating the culture of another country. One of the greatest joys in my life was giving a lecture in French at the College de France.

On returning to Princeton in 1965, I began with students a series of experiments to study the neutral CP violating decay modes of the long lived neutral K meson. These experiments lasted until 1971. In 1971 I returned to the University of Chicago as Professor of Physics. The fact that the new Fermilab 400 GeV Accelerator was being built near Chicago made this move an attractive one. At Fermilab, with younger associates and students, I carried out experiments on the production of particles at high transverse momentum, and on the production of direct leptons. At present with my colleague at Chicago, Bruce Winstein, I am preparing to study with much greater accuracy some of the CP violating parameters of the neutral K meson.

I now live in Chicago near the campus with my wife Annette, and son Daniel. My oldest daughter Cathryn lives and works in New York City. My daughter Emily attends the University of Minnesota. My mother remained in Dallas, Texas, after the death of my father in 1959. For recreation we have a cabin in the woods in Wisconsin which we visit year-round. In the summer we spend some time in Aspen, Colorado. Our whole family assembles in Chicago at Christmas and usually in Aspen in the summer.

This autobiography/biography was written at the time of the award and later published in the book series Les Prix Nobel/ Nobel Lectures/The Nobel Prizes. The information is sometimes updated with an addendum submitted by the Laureate.

James Cronin died on 25 August 2016.