The history of the field of business ethics in the U.S. remains understudied and misunderstood. In this article I begin to remedy this oversight about the past, and I suggest how it can be beneficial in the present. Using both published and unpublished primary sources, I argue that the business ethics field emerged in the early twentieth century, against the backdrop of the establishment of business schools in major universities. I bring to light four important developments: business ethics lectures at the University of California and Yale University, Leon Marshall’s curriculum at the College of Commerce of the University of Chicago, and the William A. Vawter Foundation on Business Ethics at Northwestern University. Then, I consider the payoffs of my historical account for business ethics theory, pedagogy, and practice. Specifically, I present four implications of my account under these headings: business ethics as a public problem; the place of ethics in business schools; historicizing business ethics; and historical self-knowledge.