Earlier still, it had been part of the Diocese of Boston, established in 1808 by Pope Pius VII, whose territory at the time encompassed all of New England.

With the assistance of Father Thomas B. Gloster, Pastor of St. Charles Borromeo Parish, the Diocese of Bridgeport had purchased some 11 acres of land and two houses on Shelton Road in Trumbull.

As plans for the church progressed, Bishop Shehan arranged for the Most Reverend Fulton J. Sheen, the celebrated author, television personality, and host of the award-winning television show Life is Worth Living, to present a lecture on March 22, 1957, at the Shakespeare Festival Theater in Stratford, the proceeds of which benefitted the Church Building Fund for Saint Catherine of Siena Parish.

Its stained glass windows – depicting Apostles, Religious Founders, and the patron saints of the Catholic churches in the City of Bridgeport – were fashioned in Brussels, Belgium by the firm of J. Vosch.

Recognizing the importance of handing on the gift of the Catholic Faith to new generations, by 1964 the parish had grown to the point that a school could be considered.

In 1964, construction began simultaneously on the school building and on the parish rectory, both of which were designed by William F. Griffin, AIA, a Saint Catherine's parishioner.

In September 1965, the first three classes of Saint Catherine of Siena School began: Grades 1, 2, and 7, with 71 students enrolled, originally meeting in the Church Hall.

In April 1967, Monsignor John F. McGough was named the second Pastor of Saint Catherine of Siena Parish by the Most Reverend Walter W. Curtis, the second Bishop of Bridgeport.

McGough was followed nine years later by a third Pastor, Father Richard J. Monahan, who was also appointed by Bishop Curtis, and who served Saint Catherine's until his retirement from active ministry in 1991.

The 1970s and 1980s saw continued growth, together with the completion of several special projects, including an addition to Saint Catherine of Siena School in 1987, designed by parishioner Alfred Szymanski, AIA, of Fletcher Thompson, and built by the P. Francini Construction Company of Derby, Connecticut.

Shea celebrated the 50th anniversary of his priestly ordination with a Mass of Thanksgiving at Saint Catherine's, which was attended by Bishop Lori.

These receptions were attended by thousands of the faithful and other honored guests, by hundreds of priests from the Dioceses of Bridgeport and Brooklyn and beyond, and by over thirty bishops, including the Apostolic Nuncio to the United States of America.