The program on Saturday in Chicago includes music, prayer, speeches and Pope Leo’s first public address to an American audience.

"The commitment to building a safer world free from the nuclear threat must be pursued through respectful encounters and sincere dialogue," Leo said.

In his first month, Pope Leo has taken a very different approach to his predecessor Francis. Leo, the former Cardinal Robert Prevost, has led some two dozen public events since he was elected as the first U.

The 69-year-old former Cardinal Robert Prevost, the first U.S. pope in history, has led around two dozen public events since his election on May 8, but has yet to make significant appointments, announce foreign trips,

This chart was prepared by Henry Louis Gates Jr., American Ancestors and the Cuban Genealogy Club of Miami. It reflects the best-known research as of the time of publication. Design by Nick Sheedy.

Pope Francis transformed the Catholic Church's approach to economics by prioritizing people over profits. His advocacy for worker rights and environmental sustainability has influenced business leaders and policymakers worldwide.

When the newly elected Pope Leo XIV stepped out on the central loggia of St. Peter’s Basilica to greet the crowd, liturgical fashion aficionados around the globe noticed a change. (AP video shot by Dario Artale,

With all that happened in the Catholic Church last month, we can be forgiven for missing the 10th anniversary of “Laudato si’,” Pope Francis’ encyclical on global warming. Pope Francis fell ill and died on April 21.

Pope Leo XIV made his first appointment of a Chinese bishop under the Vatican's 2018 agreement with Beijing, signalling he is continuing one of Pope Francis' most controversial foreign policy decisions.