Pope Francis on Sunday, Oct. 25, 2020, named 13 new cardinals, including Washington D.C. Archbishop Wilton Gregory, who would become the first Black U.S. prelate to earn the coveted red hat.

This was Pope Leo’s first visit to the observatory, founded in 1891 by Leo XIII. The first vision of it, however, can be traced back to the establishment by Pope Gregory XIII of a commission ...