- born May 23, 1759
- 1777: graduated Yale College
- 1786: Rector of Hopkins Grammar School, New Haven, Connecticut
- 1801: published Essays, Mathematical and Physical
- May 3, 1802 to November 14, 1803: Acting Professor of Mathematics, USMA (the professorship was not created until the law of April 29, 1812)
- Nov 1803-Oct 1812: Surveyor-General of Northwest Territory
- October 7, 1812 to August 31, 1828: Professor of Natural and Experimental Philosophy, USMA (this professorship was created by the law of April 29, 1812)
- died February 3, 1830, age 70
Jared Mansfield was born in New Haven, Connecticut on 23 May 1759. He was the son of a sea captain whose father settled in New Haven in 1639. Jared entered Yale College with the class of 1777. Unfortunately, as a result of a variety of "discreditable escapades", he was expelled in his senior year. Ten years later, in 1787, Mansfield was able to regain the esteem of the college and thus was awarded the degree of A.M. Mansfield was able to recapture that credibility due to his superb reputation as a school teacher in New Haven and Philadelphia. He became distinguished as a teacher of mathematics. In 1786, Mansfield became Rector of the Hopkins Grammar School in New Haven. In 1795, he taught at the Friend's School of Philadelphia.
In 1801, Mansfield wrote and published Essays, Mathematical and Physical. This collection of essays was considered to be the first book of original mathematical researches by a native American. The topics covered in the essays include algebra, geometry, fluxions, and nautical astronomy. This collection attracted the attention of the government and brought Mansfield into prominence "as a man of science." In 1802, President Thomas Jefferson appointed him as a Captain of Engineers in the United States Army. He was initially assigned to teach mathematics at the newly formed United States Military Academy at West Point.
The act establishing USMA provided for an engineer, in the rank of major, to be the Superintendent, and two assistant engineers, in the rank of captain, to serve as the educators of the Academy. Captain Mansfield was one of the assistant engineers and was appointed Acting Professor of Mathematics in May 1802. The initial entering class had an enrollment of ten cadets. Until 1810, there was no formal prescribed course of studies at USMA. Mansfield and his assistant taught from Hutton's Mathematics, which was a compendium of elementary information on arithmetic, algebra, geometry, trigonometry, conic sections, analytical geometry and fluxions (calculus). The text was used as a guide for very elementary instruction which depended largely on the aptitude of the student.
On 14 November 1803, Captain Mansfield was reassigned to serve as the Surveyor-General of the United States. He was tasked to survey the state of Ohio and the Northwest Territory. Captain Mansfield imported special astronomical instruments from London, England in order to properly "run the meridian lines." His procedures were to become the basis for the system of public survey. He also made astronomical observations of the comet of 1807 in order to calculate its orbit. It was said "...he practically established the first observatory in the United States in his own house near Cincinnati." His contributions warranted a town in Ohio to be named after him. In June 1812, Lieutenant Colonel Mansfield retired from the United States Army.
His retirement was short-lived for in October
1812, Mansfield was appointed to fill the newly created position of Professor
of Natural and Experimental Philosophy at USMA, with the rank of lieutenant
colonel in the Corps of Engineers. However, due to the War
of 1812, Mansfield was assigned to superintend the fortifications at London
and Stonington, Connecticut. Mansfield spent most of his time in
Connecticut, and it was not until 1814 that he was able to return to West
Point full time. In 1825, Yale College honored Mansfield by awarding
him a degree of LL.D. In August 1828, after seventeen years of service
to West Point, Mansfield resigned his chair as Professor. On 3 February
1830, during a visit to New Haven, Jared Mansfield died at seventy years
Mansfield, Jared, "A Calculation of the Orbit of the Comet Which Lately Appeared," Memoirs of the Connecticut Academy of Arts and Science, Volume I, part 1, 1810.
Mansfield, Jared, Essays, Mathematical and Physical, New Haven, 1802.
Mansfield, Jared, "Observations on the Duplication of the Cube and the
Trisection of an Angle," Memoirs of the Connecticut Academy of Arts and
Science, Volume I, part 1, 1810.
Mansfield, Jared, "On the Figure of the Earth," Memoirs of the Connecticut Academy of Arts and Science, Volume I, part 1, 1810.
Mansfield, Jared, "On Vanishing Fractions," Transactions of the American Philosophical Society, Volume I, n.s., 1818.
Appleton's Cyclopaedia of American Biography, Volume IV, D. Appleton and Company, 1888, page 195.
The Centennial of the United States Military Academy, 1802-1902, Volume I, Washington: Government Printing Office, 1904.
Cullum's Register, Volume I, page 33.
"The Department of Mathematics," Pointer View, Volume 3, Number 12, 19 March 1948.
Dictionary of American Biography, Volume VI, part 2, American Council of Learned Societies, 1961, pages 256-257.
The National Cyclopaedia of American Biography, Volume III, James
T. White and Company, 1893, page 214.
Revised by VFR, October 19, 2003