[1] Most Holy Trinity was originally known as the church of St. Thomas when it stood at the corner of Spruce Street and Boston Post Road.

The founder, Reverend Thomas McLaughlin, was a pastor in New Rochelle and visited the Mamaroneck area once a month by wagon to attend to any parochial details.

It was an old tradition that father McLaughlin visited Mamaroneck once a month, saying mass in private homes and in the "Old Red House" which stood at the bank of the Mamaroneck River near Prospect Avenue, in the rear of the Hook and Ladder Company.

Since then, succeeding pastors worked to add on to the parish with a school, convent, rectory and gymnasium.

Most Holy Trinity Parish School (1st-8th grade), current building erected in 1928, was run by the Sisters of Charity of New York.

At its inception the Sisters, living at Saint Vincent's Retreat Center (presently the hospital), traveled to and fro by surrey driven by the church custodian, Patrick Murphy.

Roof Level (Left side, front to back): Handing of the keys to Saint Peter, the Sermon on the Mount, and Jesus healing the sick.

Father Joseph Tierney is the current pastor of Most Holy Trinity-Saint Vito Parish.