Where Catholics Live in the United States, Explained in 4 Charts January 2, 2023 AM 1260 The Rock News Catholics in Mass. The Catholic population in the United States has grown by about 2 million people in the past 10 years. Post navigation Previous Previous post: Benedict XVI’s Funeral: Only 2 Countries Will Send Official DelegationsNext Next post: Remembering Benedict XVI: Pope of the Head — and the Heart