In his landmark book “The Origins of the Urban Crisis,” Tom Sugrue, the Bicentennial Class of 1940 Professor of History and Sociology, dissected the hidden history of racial discrimination and violence, suburbanization and deindustrialization that afflicted our great urban centers in the second half of the 20th century.

Not content to analyze and even criticize from the safe confines of the ivory tower, Sugrue has chosen to join the fray. Two years ago, Mayor John F. Street appointed Sugrue to the Philadelphia Historical Commission, where he now serves as vice chair. The commission, created by city ordinance in 1955, is charged with preserving the unparalleled past of our city through the designation of buildings, structures, sites, objects and districts of historical and architectural significance.

Q. Do you see a difference between being an academic historian and being a commissioner weighing competing interests and making difficult decisions about the future of Philadelphia?
A. As a 20th century urban historian, I care a lot about cities. I don’t believe in a bright line or a wall separating history and public policy or history and contemporary society. My role on the commission grows out of a belief in the importance of historians being engaged, particularly on issues where our expertise can be brought to bear.

I am lucky—not all people working in the academy have that opportunity. People working in the historical profession can find that their intellectual interests and their civic interests correspond.

I engage myself in all sorts of things, not just historic preservation. I worked as an expert witness for the University of Michigan on its affirmative action case, drawing on my work on race. I speak to community development organizations and foundations and other civic groups concerning issues related to American cities. I think that as much as possible those of us who have something to say from a scholarly vantage point have a responsibility to weigh in and engage on those issues.

Q. What is the role of historic preservation in this city?
A. Philadelphia has one of the oldest historic preservation ordinances and the result is that there are large sections of the city and many, many buildings that are represented on the historical register—that we have marked as historically significant or contribute to the fabric of the city.

Under that ordinance, the commission consists of ex officio members who are representatives of various city agencies, City Council and so forth, and then there are appointed members. One must be an architect [School of Design professor Harris Steinberg], one must be a historian—that’s where I come in, one must be an architectural historian, one must represent community organizations and one must represent developers, so they want people with various forms of expertise to bring to bear on the decisions the commission makes.

Q. In Philadelphia we talk the talk, but do we really walk the walk?
A. We are very good on designating colonial architecture and Federal-era architecture; we have far less from the Victorian period and from the 20th century on the register. I think that is an area where we have to start thinking more creatively.
It is easy to think about Philadelphia as the capital city of the early American republic, but Philadelphia was also the “workshop of the world.” It was an extraordinary industrial center and so much of the residential architecture and industrial architecture from the mid-19th century to the early 20th century reflects that economic might. We can learn a lot from that fabric and it should—more than it has been to date—come under the purview of historic preservation.

Q. Besides being “colonial-centric,” isn’t Philadelphia’s historic preservation movement really elitist?
A. Historic preservation is one tool for encouraging investment and reinvestment in the city and for attracting population. It can be a really vital ingredient of a city’s health. Buildings and neighborhoods that are preserved include both the very upscale— Rittenhouse Square—and middle and working class—Diamond Street in North Philadelphia and the Girard Estate in South Philadelphia. The beneficiaries of preserving the city’s historic fabric are far wider than the conventional wisdom would lead you to believe.

For someone who cares deeply about the future of the city—I live in Philadelphia precisely because it is not a bland, homogenous, soulless place. As someone who really cares about maintaining the rich diversity of the city and the character of its built environment, I see historic preservation as an important part of protecting and improving the quality of life in our city.

Q. Race has been a continuing motif for you as an urban historian. Where does that fit in to the historic preservation equation?
A. One of the things that make Philadelphia and other major American cities important is that they are, by and large, incredibly racially and ethnically diverse. As we think about historic preservation, both as a way of remembering the past, but also as a tool for developing and redeveloping the city, we think about the ways that race and ethnicity connect.

Philadelphia in particular has a very rich African-American history and that dovetails with our preservation goals. The other thing is that historic preservation enhances property values and adds assets not only in places like Society Hill but also in neighborhoods with working class, minority and immigrant populations. That’s really an important part of maintaining the vitality of both Philadelphia and the metropolitan area.

Q. Center City is becoming more of a residential and entertainment district rather than a center of business and commerce. Does that put pressure on the historic infrastructure as buildings lose their previous function?
A. The historic preservation ordinance gives us the responsibility to protect buildings that have been deemed historically significant or valuable, but it also gives us the leeway to recognize that sometimes things have to change in order for buildings to remain viable. Neighborhood and commercial districts aren’t preserved or pickled in formaldehyde to be unchanged forever. A powerful example of adaptive reuse of historic structures is that we have warehouses and industrial lofts that have been converted to apartments.

Q. Speaking as a non-native, are we Philadelphians too modest about what we have here?
A. Philadelphia is one of the most historically and architecturally rich places in all of the United States. I explore cities as a hobby. Some people golf, some people knit or sew, I get in my car or get on the train or the subway and go all over the city. I’ve been doing that ever since I arrived here 12 years ago.

Spending a nice afternoon checking out an obscure neighborhood in Northeast Philadelphia or walking around and looking at historically significant buildings in Society Hill or checking out ethnic restaurants on Washington Avenue is what I love to do. Whole sections of the city are chock full of buildings and places that evoke the American past—whether it’s the settlement of early America or the racial and ethnic transformation of neighborhoods.