|Member of the New York Provincial Congress|
|Member of the Committee of Safety|
|Member of the New York State Senate|
|Member of the Congress of the Confederation|
|Born||May 27, 1735|
Huntington, Province of New York
|Died||September 12, 1807 (aged 72)|
Mary Hannah Davis
(m. 1756; died 1761)
Mary Van Wyck
|Relations||Zephaniah Platt (grandson)|
|Children||14, including Jonas, Charles|
|Residence(s)||Plattsburgh, New York|
Platt was born in Huntington, Province of New York, to Zephaniah Platt (1705-1778). He was a direct descendant of Richard Platt (1603–1684), who was born in Ware, Hertfordshire, England, and settled in the Connecticut Colony.
Platt received an English education.
Zephaniah Platt practiced law in Poughkeepsie, New York, and was a member of the New York Provincial Congress (1775–1777), Committee of Safety (1777), State Senate (1777–1783), Congress of the Confederation (1785 and 1786), Council of Appointment (1778 and 1781). He was a Dutchess County judge from 1781 to 1795 and delegate to the New York Constitutional Convention in 1788.
In 1788, he founded the town of Plattsburgh in New York, and moved there in 1798 to continue practicing law. He was an originator of the Erie Canal, and was a regent of the University of the State of New York from 1791 until his death, in Plattsburgh, in 1807.
Platt was married twice, first to Mary Hannah Davis (1741–1761) in 1756 and had two children:
- Zephaniah Platt (1756–1830)
- Hannah Comstock Platt (b. 1758)
In 1761, he married Mary Van Wyck Platt (1742–1809) and had 12 children including:
- Jonas Platt (1769–1834), who was a U.S. Representative for the 9th Congressional District of New York (1799–1801), lawyer and associate justice of the New York State Supreme Court
- Charles Z. Platt (1773–1822), who was a New York State Assemblyman for Oneida County (1807–1813) and New York State Treasurer (1813–1817)
- James Platt (1788–1870), who married Eliza Floyd, daughter of William Floyd, and had four children. After Eliza's death, he remarried twice, first to Susan Katharine Auchmuty, and secondly, as his third wife, to Sarah (née Breese) Lansing, widow of Bleeker Lansing and sister of Rear Admiral Samuel Livingston Breese and U.S. Senator Sidney Breese.
Platt owned two slaves in his lifetime, a man named "Tone" and a man named "Cato." Tone was manumitted in 1795, whereas Cato was manumitted by the Executor of his will, Jonas Platt, in 1808, four months after his death.
- "Zephaniah Platt Papers, 1745-1846; bulk, 1785-1800". nysl.nysed.gov. New York State Library. Retrieved 29 September 2017.
- Platt, George Lewis (1891). The Platt Lineage: A Genealogical Research and Record. T. Whittaker. p. 101. Retrieved 29 September 2017.
- "PLATT, Zephaniah - Biographical Information". bioguide.congress.gov. Biographical Directory of the United States Congress. Retrieved 29 September 2017.
- New York (State) Dept. of State (1868). Calendar of Historical Manuscripts, Relating to the War of the Revolution, in the Office of the Secretary of State, Albany, N.Y. Weed, Parsons & Company, Printers. p. 86. Retrieved 29 September 2017.
- Lamb, Martha Joanna (1880). History of the City of New York: Its Origin, Rise, and Progress. A. S. Barnes. p. 31. Retrieved 29 September 2017.
- Office, New York (State) Secretary's (1864). Calendar of N.Y. Colonial Manuscripts, Indorsed Land Papers: In the Office of the Secretary of State of New York. 1643-1803. Weed, Parsons & Company. p. 734. Retrieved 29 September 2017.