Monsignor Frederick R. McManus, 82, a former professor, dean and academic vice president at Catholic University and an influential figure in the post-Vatican II Roman Catholic Church in the United States, died of congestive heart failure Nov. 27 at Massachusetts General Hospital in Boston. He lived in the District until 1999, when he moved to Regina Cleri, a residence for retired priests in Boston.

Monsignor McManus's fields of specialty were canon law and the liturgy. During his career at Catholic University from 1958 to 1993, he influenced several generations of church lawyers as a professor and then dean of the School of Canon Law. He also served as vice provost and dean of graduate studies from 1974 to 1983 and academic vice president from 1983 to 1985.

Working closely over the years with other Catholic universities and bishops, he made the case to the Vatican for academic freedom among U.S. Catholic universities.

Jim McManus, a former Washington bureau chief for the National Catholic Reporter, noted that his uncle was part of a generation of priests -- including Richard McBrien at the University of Notre Dame, J. Donald Monan at Boston College, Joseph Cardinal Bernardin in Chicago and Cardinal Theodore E. McCarrick in Washington -- who shared an appreciation for the fact that the church was changing and recognized that it needed to change.

"The laity was moving into positions of responsibility, and they weren't threatened by that," Jim McManus said.

As a young priest, Monsignor McManus served as peritus, or expert, to the American bishops who attended the Second Vatican Council from 1962 to 1965.

At the Vatican Council, he was involved in drafting the Constitution on the Sacred Liturgy.

"He was the one who breathed the Holy Spirit into the liturgy document," said Monsignor James Tierney, director of Regina Cleri and a longtime friend.

A 1964 article in the New York Times said that in his role as peritus, Monsignor McManus was both adviser and counselor to bishops, archbishops and cardinals and met daily with English-speaking journalists.

"The handsome, dark-haired priest answered countless questions faultlessly. Some of the queries were tough, others abysmally stupid," the article said. "But Father McManus never lost his temper or his unfailing good temper."

In recognition of his service, Monsignor McManus was given the honor of celebrating the first English-language Mass in the United States, in 1964 in St. Louis.

The author of seven books and numerous scholarly articles on the role of the laity in the liturgy and canon law, he contributed to the revision of the church's Code of Canon Law in 1983. He was editor of the Jurist, Catholic University's canon law journal, for more than 30 years, beginning in 1959.

Frederick Richard McManus was born in Lynn, Mass. He attended the College of the Holy Cross, graduated in 1947 from St. John's Seminary in Brighton, Mass., and was ordained that year. He received his doctorate in canon law from Catholic University in 1954. He served as master of ceremonies to Cardinal Richard Cushing of Boston before assuming his duties at Catholic University.

He was one of the founders of the International Commission on English in the Liturgy and served in numerous roles in the organization until the late 1990s.

In the 1980s and 1990s, he represented the Catholic Church in ecumenical dialogues with the Anglican and Eastern Orthodox churches. The dialogues were established by Pope John Paul II. He also participated in the North American Orthodox-Catholic Theological Consultation and the international commission established to explore common ground with the Orthodox Church.

Monsignor McManus was a tennis buff. His father played on the Holy Cross tennis team in 1918, and he, too, played as a young man. In later years, he was frequently in the stands at Wimbledon, the French Open, the U.S. Open and other major tennis events. He also loved reading mysteries, particularly those featuring Nero Wolfe. Walking was his exercise of choice; he loved strolling through Washington and Rome.

He had no immediate survivors.

The monsignor was also a dean.