Henry Arnold Coster (1840-1917)

He was the grandson of one of New York's first five millionaires, John G. Coster, and through his mother he was a descendant of Stephen DeLancey (1663-1741). In 1866, at Boston, he married Mary, daughter of Isaac Underhill Coles, and they were the parents of two children. Harry and Mary were among Mrs Astor's "400". They divided their time between their townhouse in New York City (2 East 41st Street); their country house, the Coster Mansion at Throgg's Neck; and, their summer house in Newport, R.I. After Harry's death, his widow lived between 50 East 81st Street and the summer home she bought after selling the Coster Mansion, "Wee Cot," Southampton.