No twentieth-century event had a more direct or significant impact on the Catholic Church around the world than the Second Vatican Council, a meeting of all the Church's bishops, along with theologians and observers. Among other documents, the Council produced a constitution urging the Church to engage the world, a constitution on the liturgy that led to dramatic changes in liturgical practices, and a declaration that embraced religious freedom. Filtered into an American Church immersed in the cultural upheaval of the 1960s, the texts of Vatican II became a battlefield on which rival interpretations of the Church, the nature of change in the Church, the roles of laity, priests, and bishops, and other issues, fought for dominance over the ensuing decades.