The Second Vatican Council's Constitution on the Liturgy set in motion a series of changes that would dramatically change the face of the Catholic Mass. Among the most obvious revisions, the document called for the use of vernacular languages instead of the traditional Latin, and for increased participation of the laity in prayer and song. Many of the modifications reflected the advocacy of an international liturgical reform movement, which had for several decades had a presence in the United States, in particular in places such as the Benedictine monastery of St. John in Minnesota.
In the United States, as elsewhere, the changes were met with reactions ranging from enthusiastic acceptance to hostile rejection. The liturgy would become and remain one of the key battlegrounds in the post-Vatican II era fight over the question of how most authentically to interpret the Council.