Why is "American urban history" trending?

Wikipedia Overview

American urban history is the study of cities of the United States. Local historians have always written about their own cities. Starting in the 1920s, and led by Arthur Schlesinger, Sr. at Harvard, professional historians began comparative analysis of what cities have in common, and started using theoretical models and scholarly biographies of specific cities. The United States has also had a long history of hostility to the city, as characterized for example by Thomas Jefferson's agrarianism and the Populist movement of the 1890s. Mary Sies (2003) argues:At the start of the twenty-first century, North American urban history is flourishing. Compared to twenty-five years ago, the field has become more interdisciplinary and intellectually invigorating. Scholars are publishing increasingly sophisticated efforts to understand how the city as space intersects the urbanization process, as well as studies that recognize the full complexity of experiences for different metropolitan cohorts.