April 16, 1957 -- Bishop Walter P. Kellenberg is appointed first Bishop of Rockville Centre by Pope Pius XII.

May, 1959 -- The first group of priests are appointed monsignors.

May 12, 1964 -- Bishop Kellenberg is the first bishop to celebrate Mass at Vatican Pavilion in World's Fair.

Oct. & Nov., 1966 -- Four diocesan high schools are dedicated.

November 12, 1970 -- Most Rev. John R. McGann is appointed Auxiliary to the Bishop of Rockville Centre.

October 27, 1971 -- Episcopal Vicars in the Rockville Centre Diocese, Bishop Baldwin for Nassau and Bishop McGann for Suffolk, are appointed.

January, 1974 -- First March for Life in Washington, D.C.

May 3, 1976 -- Bishop Kellenberg's retirement accepted by Pope Paul VI in accord with the norms for the retirement of bishops at age 75. Most Rev. John R. McGann is appointed second Bishop of Rockville Centre.

June, 1979 -- First group (48) of permanent deacons is ordained.

October, 1979 -- Pope John Paul II visits New York City.

October, 1980 -- Immaculate Conception Seminary has 50th anniversary.

October, 1981 -- Bishop McGann opens Holy Year, celebrating the diocese's 25th anniversary.

January 11, 1986 -- Bishop Walter P. Kellenberg passed away.

December 7, 1998 -- Most Rev. James T. McHugh is appointed Coadjutor Bishop of Rockville Centre.

January 4, 2000 -- Bishop John R. McGann retires and Most Rev. James T. McHugh Succeeded to See as third Bishop of Rockville Centre.

December 10, 2000 -- Bishop James T. McHugh passed away.