On May 8, 2025, Chicagoans were surprised to hear that the College of Cardinals selected one of their own to serve as the next Pope. Chicagoans understand how the characteristics of their city—that is both parochial and cosmopolitan—helped prepare Pope Leo XIV to assume his post as leader of the universal Church. What makes “Pope Bob,” as he is now affectionately called by locals, a product of Chicago and the Midwest? His family history represents the diverse migration and immigration streams that are represented in Chicago’s population.

We will consider how the pope’s family’s genealogy reflects the streams of migrants and immigrants to Chicago. While the Yankee Protestant settlers who came to Chicago tried to exclude Catholics from the mainstream, Chicago became an immigrant and Catholic city. By the mid-twentieth century, Catholics comprised 35 percent of the city’s population, and the Archdiocese of Chicago emerged as one of the largest and most diverse in the country. There were more Polish Catholics in the Chicago than in Warsaw. In the Archdiocese of Chicago today Latino Catholics make up half of the laity and African Americans comprise 11 percent.

Because of Chicago’s ethnic pluralism, its readiness to embrace new structures, and the importance of the local parish, a robust Catholic educational, medical, and social infrastructure emerged that wielded considerable influence. Pope Leo grew up in this Catholic milieu. We will unpack how the Catholic infrastructure of parishes, schools, and hospitals, created by clergy, religious, and laity, influenced his early life. His parents supported the extension of schools and parish infrastructure into the south suburbs. Schools and gyms mattered as much, if not more than the churches. This culture thrived after World War II and then declined in the closing decades of the twentieth century. Urban historians have not been kind to these folks, depicting them as angry Catholic homeowners.

Catholic Chicago extended beyond the geographical region, as part of a global church. Religious orders and the diocese both supported missionary activities that took Chicagoans like Robert Prevost around the world.