Walsh has asked the Roman Catholic Cardinal of Boston, Sean O'Malley, to hand deliver an invitation to the pontiff asking him to visit Boston during a possible visit to the U.S. next year. O'Malley headed to the Vatican this week. According to The Boston Globe, Walsh's letter emphasizes the importance of the church in his own life as well as the importance of faith in the history of the city. He points out that the Boston Archdiocese is one of the largest in the U.S. The last and only time a pope visited Boston was 1979, when Pope John Paul II held a Mass for thousands on Boston Common during a downpour.