McCray grew up in rural southwestern Pennsylvania and later attended graduate school at the University of Arizona where he completed a Ph.D. in 1996. He is the author or editor of several books on the history of science and technology; topics include the effects of technology on astronomical practice, the activities of amateur scientists during the Cold War, and the activities of scientists who promoted radical visions for the technological future. More recently, McCray has studied and written about the interactions between art and technology. A new book, called Making Art Work, appeared in 2020 and documents interactions between engineers and artists from the 1960s to the present.
Prior to this, in his 2013 book The Visioneers, McCray presented the concept of "visioneer" as historical actor. As he defined it, the term is a portmanteau that refers to individuals (often with a science or engineering background) who imagined, designed, and built exploratory technologies. The Visioneers won the 2014 Watson Davis and Helen Miles Davis Prize Watson Davis and Helen Miles Davis Prize from the History of Science Society.