In 1980, he began his academic career as a professor in the Department of Art History at the University of Illinois at Chicago, where he eventually was named director of the American Studies Institute.
In 2006, Hales published an extensively revised and enlarged version of his first book, now renamed Silver Cities: Photographing American Urbanization, 1839–1939; the revised version included more sophisticated studies of race, ethnicity and gender, and extended the work well into the 20th century, including studies of the urban photography of the Farm Security Administration.
In the beginning of the 21st century, Hales' attention turned to the virtual world, both as subject and as means of gathering and presenting historical and cultural information.
With his UIC colleague Robert Bruegmann, Hales developed a website collecting and organizing visual documentation of the Chicago built environment, the Chicago Architecture Imagebase [1]; in addition, he developed a collaborative public-history project on the postwar American suburb, Levittown, Long Island, [2] In April 2014, Hales' work, Outside the Gates of Eden: The Dream of America From Hiroshima to Now—a continuation of his Silver Cities project—was released.
[6] In the early evening of August 26, 2014, Hales — who was an avid bicycle enthusiast — was killed in an accident involving a motor vehicle near his post-retirement home in Stone Ridge, New York.