As Father Higgins' health sank, his two assistants strove to complete the building of the church. Eventually, Father Maguire succeeded in raising the necessary funds, and construction began in 1848. However, Father Higgins never lived to see its completion; he died in August of that year back in Ireland, after receiving a leave of absence because of ill health.

Fittingly named St. Matthew's, the new church probably did not seat more than 150 people. New Rochelle was still officially only a mission chapel, with neither a pastor nor a rectory.

Father Edward J. O'Reilly succeeded Father Higgins as the first resident pastor. He raised sufficient funds to enlarge St. Matthew's, and founded two other churches, in Port Chester and White Plains. Like his predecessor, Father O'Reilly wore himself out making the long journeys among his widely scattered flock. His health shattered, he was transferred back to New York, and in October, 1853, the Reverend Thomas McLoughlin succeeded to the pastorate of New Rochelle and its missions. "Old Father Tom," as he came to be known affectionately, was the last and the greatest of the pioneers.

Father Tom's parish embraced all of New Rochelle, and missions in Mamaroneck, Port Chester, White Plains, Tuckahoe, City Island, Rye, Pelhamville, and Harrison. A typical Sunday morning would find him driving his wagon from New Rochelle at six to visit one of his missions in other towns miles away, hearing confessions, offering Mass, and returning to New Rochelle for 10:30 Mass at St. Matthew's.

Father Tom helped build churches at Tuckahoe, Mamaroneck, and Larchmont. As other priests were assigned to them and other missions, he was able to give his full attention to his own parish. He turned his attentions to building a parochial school next to the church, and ultimately, to building a new church itself. St. Matthew's had already been enlarged twice, and 800 parishioners were routinely crowded into its 500 seats. Unfortunately, there was no more room left for further expansion at its present site. Accordingly, he purchased a choice lot on Centre Avenue at the corner of Beauchamp Place.

Four years passed as the building fund grew slowly. At last, in the spring of 1873, digging for the foundation was begun. Because of a financial panic that gripped the nation, funds to continue building the church dried up, and so modifications were made to the original plans to cut costs -- including the abandonment of a planned rectory. With the help of an emergency mortgage loan, the building was finally completed. On June 7, 1874, the large wooden structure was dedicated by Archbishop McCloskey. Because of Father Tom's devotion to the Blessed Sacrament, the church was renamed the Church of the Blessed Sacrament.

The strain of meeting payments on the mortgage of the new church, operating the old church as a chapel for the Lane, and carrying the burden of the parish school and convent became too great, and so Father Tom closed his parochial school on Drake's Lane.

As Father Tom struggled to cultivate the financial means to reopen the school, he wrote a Catechism for the parish children, which has since been widely published, and trained young women to teach Sunday School. In September of 1880, three months after the 27th anniversary of his pastorate, the seemingly impossible became a reality when a new parish school was opened. Building the structure had been an historic parish enterprise. It consisted of dismantling the old church on Drake's Lane, carrying its bricks over a mile of roads to the new site, and rebuilding them into a schoolhouse that was a replica of the original church. It was located on the north side of the new church on Centre Avenue, and retained the name of St. Matthew's School.