In earlier eras, church leaders in the United States had accommodated ethnic diversity by establishing an array of “national” parishes. By the 1970s, American Catholics had come to see their diversity not as an obstacle to overcome, but a blessing to embrace. Reflecting on the legacy of the 1976 Eucharistic Congress, the “heritage” liturgies speak to broader changes taking place within American Catholic life and reveal a new embrace of diversity within the church. ***This article was written in partnership with the American Catholic Historical Society and the Catholic Historical Research Center of the Archdiocese of Philadelphia. Thomas F. Rzeznik is professor of history at Seton Hall University and co-editor of the quarterly journal, American Catholic Studies.