Pope Leo XIII sought to find a way forward for the Catholic church at a time when the world was rapidly changing and the church was often at odds with those changes.

Research:

• Aubert, Roger-François-Marie. "Leo XIII". Encyclopedia Britannica, 18 May. 2025, https://www.britannica.com/biography/Leo-XIII
• “ELECTION OF POPE LEO XIII.” New York Times. Feb. 21, 1878. https://timesmachine.nytimes.com/timesmachine/1878/02/21/issue.html
• Jedin, Hubert and John Patrick Dolan. “History of the Church: The Church in the Industrial age.” Burns & Oates. 1981. https://books.google.com/books?id=h5LYAAAAMAAJ&source=gbs_navlinks_s
• Masci, David. “A look at popes and their encyclicals.” Pew Research Center. June 9, 2015. https://www.pewresearch.org/short-reads/2015/06/09/a-look-at-popes-and-their-encyclicals/
• Miller, James Martin. “The life of Pope Leo XIII : containing a full and authentic account of the illustrious pontiff's life and work.” G.H. Harr. Omaha, Nebraska. 1908. Accessed online: https://archive.org/details/lifeofleo1300milluoft/page/n5/mode/2up
• O’Reilly, Bernard. “Life of Leo XIII, from an authentic memoir furnished by his order.” Sampson Low, Marston & Co. London. 1903. https://archive.org/details/lifeofleoxiiifro0000orei/page/n9/mode/2up
• Pope Leo XIII. “AETERNI PATRIS.” 1879. https://www.vatican.va/content/leo-xiii/en/encyclicals/documents/hf_l-xiii_enc_04081879_aeterni-patris.html
• Pope Leo XIII. “INSCRUTABILI DEI CONSILIO.” 1878. https://www.vatican.va/content/leo-xiii/en/encyclicals/documents/hf_l-xiii_enc_21041878_inscrutabili-dei-consilio.html
• Pope Leo XIII. “RERUM NOVARUM.” https://www.vatican.va/content/leo-xiii/en/encyclicals/documents/hf_l-xiii_enc_15051891_rerum-novarum.html
• Pope Leo XIII. “Testem Benevolentiae Nostrae.” 1899. https://www.papalencyclicals.net/leo13/l13teste.htm
• “Religious.” Chicago Tribune. February 24, 1878. https://www.newspapers.com/image/349728621/?match=1&terms=Pope%20Leo%20XIII
• “Vatican country profile.” BBC. Nov. 17, 2023. https://www.bbc.com/news/world-europe-17994868