So strong was the connection of Mamaroneck with Rye as a part of that Parish, in fact and in feeling, that it continued practically down to the founding of St. Thomas' Church, Mamaroneck. All Mamaroneck people of the Episcopal Church attended at Rye church, and were married and buried, and their children baptized, by the Rectors of Rye. A very few went to the New Rochelle church but the large majority went to Rye. It was simply an example of the power of fkith and habit which descended to them from their ancestors.

While a youth in Yale College the late Rt. Rev. William Heathcote de Lancey first began holding Episcopal services in Mamaroneck while on his visits to his home at Heathcote Hill. He entered college in 1813 and graduated in 1817, and these services began in 1814. He met with better success than he anticipated. His Father John Peter De Lancey took great interest in the matter, as did his friend and neighbor Mr. Peter J. Munro, and Mr. and Mrs. Peter Jay, the blind Mr. Jay, of Rye. Finally young Mr. de Lancey was so successful that on April 12th, 1814, under the auspices of his Father and Mr. Peter J. Munro a parish was organized under the old act of 17th March, 1795, to which was given the name of St. Thomas. Mr. John Peter de Lancey and Mr. Peter Jay Munro Church Wardens, and Capt. William Gray, Benjamin Hadden, Henry Gedney, Samuel Deal, Abraham Guion, and Matthias G. Valentine Vestrymen * at the first election held on Tuesday in Easter week of that year. The Rev. Mr. Haskell Rector of Rye and several of the clergy of the neighbouring parishes took charge of the services, which were held in the present Town Hall, then a Methodist Church just built, by the courtesy of that Society which had just previously been organized.