{{Short description|American politician (1769–1834)}} {{distinguish|Jonas M. Platt}} {{infobox officeholder | image = Brooklyn Museum - Jonas Platt - Samuel Finley Breese Morse - overall.jpg | caption = ''Portrait of Platt, by Samuel F. B. Morse, 1828'' | office1 = Member of the New York State Senate | term_start1 = July 1, 1809 | term_end1 = June 30, 1813 | predecessor1 = | successor1 = | state2 = New York | district2 = 9th | term_start2 = March 4, 1799 | term_end2 = March 3, 1801 | predecessor2 = John Williams | successor2 = Benjamin Walker | office3 = Member of the New York State Assembly | term_start3 = July 1, 1795 | term_end3 = June 30, 1796 | birth_date = {{birth date|1769|06|30}} | birth_place = Poughkeepsie, Province of New York, British America | death_date = {{death date and age|1834|02|22|1769|06|30}} | death_place = Peru, New York, United States | party = Federalist | parents = Zephaniah Platt<br>Mary Van Wyck Platt | spouse = Helena Livingston | children = 8, including Zephaniah | relations = Charles Z. Platt (brother) }} '''Jonas Platt''' (June 30, 1769 – February 22, 1834) was an American lawyer and politician from New York. He was a member of the United States House of Representatives.<ref name="JPbioguide">{{cite web |title=PLATT, Jonas - Biographical Information |url=https://bioguide.congress.gov/scripts/biodisplay.pl?index=P000381 |website=bioguide.congress.gov |publisher=Biographical Directory of the United States Congress |accessdate=5 July 2018 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304002437/http://bioguide.congress.gov/scripts/biodisplay.pl?index=P000381 |url-status=live }}</ref>

==Early life== Platt was born on June 30, 1769, in Poughkeepsie, Province of New York, in what was then British America.<ref name="nycourts">{{cite web |title=Jonas Platt {{!}} Associate Justice of the New York Supreme Court of Judicature, 1814-1823 |url=http://www.nycourts.gov/history/legal-history-new-york/luminaries-supreme-court/platt-jonas.html |website=www.nycourts.gov |publisher=New York Courts |accessdate=15 April 2019 |archive-date=15 April 2019 |archive-url=https://web.archive.org/web/20190415193209/http://www.nycourts.gov/history/legal-history-new-york/luminaries-supreme-court/platt-jonas.html |url-status=live }}</ref> He was the son of patriot politician and lawyer Zephaniah Platt (1735–1807), who founded Plattsburgh, New York, and his second wife, Mary Van Wyck Platt (1742–1809). Among his siblings was New York State Treasurer Charles Z. Platt.<ref name="Platt1891"/>

After attending a French Academy at Montreal, Quebec, Platt studied law under Richard Varick in New York City<ref>{{Cite web |title=Jonas Platt |url=https://history.nycourts.gov/figure/jonas-platt/ |access-date=2025-07-17 |website=Historical Society of the New York Courts |language=en-US}}</ref> and was admitted to the bar in 1790.<ref name="JPbioguide"/>

==Career== He practiced law in Poughkeepsie and served as the county clerk of Herkimer County, New York, from 1791 to 1798. He was also the county clerk of Oneida County, New York, from 1798 to 1802. He was a member of the New York State Assembly in 1796.<ref name="JPbioguide"/>

Platt was elected as a Federalist to the 6th United States Congress, and served from March 4, 1799, to March 3, 1801. He was the Chair of the United States House Committee on Revisal and Unfinished Business.

Following his Congressional service, Platt resumed practicing law in New York and concurrently served as a General in the Cavalry in the New York State Militia.

Platt served as a member of the New York State Senate from 1809 to 1813. As a member of the Senate, Platt was an active promoter of the Erie Canal and worked to advance legislation to spur its construction.<ref>{{Cite web |title=History of the New York State Canals |url=https://www.canals.ny.gov/About/History |access-date=2025-07-17 |website=NYS Canals |language=en}}</ref>

In 1810, he was an unsuccessful candidate for governor, and in 1813, served as a member of the Council of Appointment.<ref name="JPbioguide" />

From 1814 to 1821, Platt was an associate justice of the New York Supreme Court. He was a delegate to the New York Constitutional Convention in 1821.<ref name="JPbioguide"/>

==Personal life== He married Helena Livingston (1767–1859), the daughter of Dr. Henry Livingston and Susannah Storm (née Conklin) Livingston, of the Livingston family.<ref name="Livingston1910"/> She was also the sister of Continental Congressman Gilbert Livingston, the Rev. Dr. John Henry Livingston, president of Queen's College, and author Henry Livingston Jr. (the grandfather of U.S. Senator Sidney Breese and Admiral Samuel Livingston Breese), among others.<ref name="Livingston1910">{{cite book|last1=Livingston|first1=Edwin Brockholst|title=The Livingstons of Livingston Manor: Being the History of that Branch of the Scottish House of Callendar which Settled in the English Province of New York During the Reign of Charles the Second; and Also Including an Account of Robert Livingston of Albany, "The Nephew," a Settler in the Same Province and His Principal Descendants|date=1910|publisher=Knickerbocker Press|url=https://archive.org/details/livingstonslivi00unkngoog|accessdate=July 5, 2018|language=en}}</ref> Together, Jonas and Helena were the parents of eight children, including:<ref name="Livingston1910"/>

* Susan Jonasse Platt (1793–1843), who married Richard Ray Lansing (d. 1855).<ref name="Platt1891"/> * Zephaniah Platt (1796–1871), the Michigan Attorney General.<ref name="Platt1891"/> * Helen Livingston Platt (1798–1876), who married Truman Parmelee (1801–1845).<ref name="TWPObit1893">{{cite news |title=Col. Theodore Weld Parmele. |url=https://timesmachine.nytimes.com/timesmachine/1893/05/15/106864842.pdf |accessdate=15 April 2019 |work=The New York Times |date=15 May 1893 |archive-date=31 August 2021 |archive-url=https://web.archive.org/web/20210831203321/https://timesmachine.nytimes.com/timesmachine/1893/05/15/106864842.pdf |url-status=live }}</ref> After his death, she married Dr. Henry W. Bell.<ref name="Platt1891">{{cite book |last1=Platt |first1=George Lewis |title=The Platt Lineage: A Genealogical Research and Record |date=1891 |publisher=T. Whittaker |page=[https://archive.org/details/plattlineageage00platgoog/page/n129 124] |url=https://archive.org/details/plattlineageage00platgoog |accessdate=12 April 2019 |language=en}}</ref>

Platt died on February 22, 1834, in Peru, Clinton County, New York and was buried at the Riverside Cemetery in Plattsburgh.<ref name="JPbioguide"/>

==References== {{reflist|30em}}

==External links== * {{CongBio|P000381}} * {{find a Grave|12139970}} * [http://www.iment.com/maida/familytree/henry/genealogy/robert2.htm Livingston family tree]

{{s-start}} {{s-ppo}} |- {{s-vac|last=Aaron Burr<br>{{small|Endorsed}}}} {{s-ttl|title=Federalist nominee for Governor of New York|years=1810}} {{s-aft|after=Stephen Van Rensselaer}} {{s-par|us-hs}} {{US House succession box | state=New York | district=9 | before=John Williams | after=Benjamin Walker | years=1799&ndash;1801 }} {{s-end}}

{{Authority control}}

{{DEFAULTSORT:Platt, Jonas}} Category:1769 births Category:1834 deaths Category:Members of the New York State Assembly Category:New York (state) state senators Category:Politicians from Poughkeepsie, New York Category:Politicians from Herkimer County, New York Category:New York Supreme Court justices Category:Livingston family Category:Federalist Party United States representatives from New York (state) Category:19th-century New York state court judges Category:19th-century members of the New York State Legislature Category:18th-century United States representatives Category:18th-century members of the New York State Legislature Category:Candidates in the 1810 United States elections