[1] In his early years, he was a coachman to Boston merchant William Gray and moved to New York in 1795.

[2] After opening his own private bank, he allowed customers to deposit money and then loaned it out.

Prime and his family lived in a house on the corner of Broadway and Battery Place.

William H. Aspinwall served on the coroner's jury, and Edgar Howland informed diarist George Templeton Strong that: "Prime went to his room at two o'clock and appears to have taken up and read his prayer book, then went before the glass, cut his throat coolly and steadily from ear to ear, replaced the razor in its case, and then walked into the next room, and there fell.

He had been dyspeptic and nervous for some time; he was retired from active life and his mind, I suppose, preyed on itself for want of occupation ..."[11]Through his daughter Cornelia, he was the grandfather of Cornelia Ray (1829–1867), who married Gen. Schuyler Hamilton (1822–1903), a grandson of Alexander Hamilton; Robert Ray (1832–1860), and Nathalie Elizabeth Ray (1837–1912), who married Edmund Lincoln Baylies (1829–1869), the parents of Edmund L. Baylies Jr.[12] Through his daughter Emily, he was the grandfather of author, novelist and popular science writer William Seton III (1835–1905),[13] Robert Seton (1839–1927), a monsignor in the Roman Catholic Church and titular archbishop of Heliopolis.

[10] William's children included Charlotte Hoffman Prime (1881–1969), who married William Massena Benjamin (1874–1928), the son of Samuel Nicholl Benjamin; and Charlotte Prime (b.