Watch Pope Leo XIV’s historic inaugural Mass in Vatican City. Leo is the first American pope, marking a major moment for American Catholics. For more context and news coverage of the most important stories of our day click here: https://www.msnbc.com/ » Subscribe to MSNBC: https://www.youtube.com/msnbc » Subscribe to MSNBC on TikTok https://www.tiktok.com/@msnbc » Subscribe to…