The institution was founded here in 1856, when this site was still in Westchester County, Nearly a thousand Sisters, in more than a hundred subordinate houses, including asylums, hospitals, the Girls' Protectory in Westchester, the retreat for the insane at Harrison, industrial schools, academies and parish schools, are governed from Mt. St. Vincent. The many parish and other schools, under the Sisters of Charity from this house, and situated in Westchester County and in and near New York, include about thirty-five thousand pupils, besides the hundreds of sick and infirm in their different asylums and hospitals.

The Sisters of Charity are a benevolent corporation of women only, formed under the general laws of the State of New York, and governed by their own trustees elected from among themselves, and are largely independent. The Mother Superior is the president of the corporation. Mother Angela Hughes, the youngest sister of Archbishop Hughes, was superior of the order when the Sisters, in December, 1856, bought this property of Edwin Forrest, with the farm buildings and the castle upon it, as he had built them for his own residence.- The following year Mother Angela commenced the new building, which now forms the central part of the present convent, overlooking the Hudson, between two and three hundred yards distant. This first building, with a front of two hundred and seventy feet, has by later additions been enlarged to more than five hundred feet of frontage, making a handsome brick structure, three stories in height, with high basement and attic and a lofty spire.