There are several genealogies of the Cooper family. The oldest is a family Bible, written in Dutch. Miss Grace Wilmarth privately printed in 1946 a genealogical history of the family under the title Obadiah Cooper (Tailor at Albany 1713-1742) His Wife, Cornelia (Gardenier) Cooper, and their Descendants.
Of several genealogical websites, the entire family tree, maintained by the Hewitt family, can be explored on the MyHeritage website at https://www.myheritage.com/site-family-tree-67285031/hewitt-family-tree?rootIndivudalID=1000149&familyTreeID=1.
One of many difficulties in tracing the Cooper family tree is the ubiquitousness of the Cooper/Kuyper/Cuyper family name, as reflected in this 58 page document, much of it sourced from the libraries' primary joint source, Heritage Quest: http://njgsbc.org/files/BCFamilies/BCFam-Cooper.pdf.
English or Dutch?
Where this [second] Obadiah Cooper came from is a mystery. According to family tradition he was English and his father was one of three brothers who came to America in 1662. If the Cooper family was English, it seems very curious that the entries in the family Bible were written in Dutch until well into the eighteenth century, and equally strange that Obadiah's children should have Dutch, not English names. The Coopers were certainly either Dutch or had adjusted to and been completely accepted by the Dutch community. As a matter of fact, Coopers of all generations married Englanders and Hollanders and Huguenots with a fine disregard for ancestry, suggesting how completely national lines were broken down among the farmers and artisans of the Hudson Valley. The one solid fact that remains is the existence of Obadiah the tailor in the Albany directory of 1713.
Albany to Fishkill
Cooper's ancestors were not, then, to be great landowners to rival the Van Cortlandts and the Van Renssalaers; nor were they to have the capital to invest in shipping and to lend money to farmers and manufacturers and thus grow rich. Peter's grandfather's heirs - seven in number - realized a total of six hundred pounds on their joint inheritance. But the Coopers were also not among that impoverished lower class of itinerant artisans and laborers and servants which swelled the population in the eighteenth century and led to so many conflicts over voting privileges and debts. This should particularly be kept in mind when we hear [Peter] Cooper tell countless audiences of Cooper Union students and workingmen how he, too, was a workingman and had risen from nothing to affluence by hard work. Peter himself was well aware in his less sentimental moments that he did not start entirely from scratch, and was displeased when a writer in Frank Leslie's Popular Monthly alluded to his parents as poor and obscure and to himself as self-made. From the days of Obadiah Cooper for three-quarters of a century, until Peter's birth, the Coopers were master artisans and well-to-do farmers, part of that great middle stratum of society that was later to lead an independent America to industrial greatness.
Their family motto was Perseverance conquers all things, and most of them followed its dictum. While their father was alive his children remained around him, but after his death in 1742 most of them struck out down the river on their own. Obadiah, Peter's grandfather, the fourth son, stayed in Albany until the death of his first wife, Maria Fonda, a descendant of one Jellis Fonda, who settled in the Albany region as early as 1651. Maria died in the fifth year of their married life, in 1748, as did their two-year-old son Pieter. Obadiah, then aged twenty-eight, with his daughter Cornelia followed two of his older brothers into the region of Dutchess County broadly called Fishkill.
A single story remains, and it indicates a certain shrewd humor and cynicism. A neighbor of Obadiah's complained bitterly one day that his three sons were all born under unlucky planets, one to be a beggar, one a thief, and one a murderer. "What in the world do you worry about them for?" asked Obadiah. "It is not worth your while to grieve away your life about them. . . . If you will take my advice your sons will all go through the world respecably. The one that is born to be a beggar, make a minister of him; and the one that is born to be a thief, make a lawyer of him and he will pick people's pockets and they will have the desire for it; and the one that is born to be a murderer, make a doctor of him."
Difficulty of Genealogy
Margaret's parents, John and Sarah (Oakley) Campbell, were old New Yorkers, both having been born in New York City, and John Campbell [Peter's paternal grandfather] was one of the town's more important citizens. Owner of a tile- and pottery-making establishment, and of a number of houses on Broadway on the old Duane property, he was a man of considerable wealth. Before the Revolution he had been a major in the old state militia. When war broke out he was appointed by Washington deputy quartermaster general in the Continental Army and entrusted with the protection of the citizens of lower New York State. He was a very remarkable man and the great hero of his grandson. Though Peter met him only once, when as a boy of six or seven he took a brief ride in his grandfather's gig on the latter's visit to Peter's father in Peekskill, memory of the short, thickset old man haunted his grandson's thoughts for the rest of his life.
[John Campbell, Peter's paternal grandfather]'s widow lived on a good many years and was the only one of his grandparents whom Peter really knew. As a boy he visited her frequently, and when he came to New York as an apprentice she let him use the back room of one of her Broadway houses. The kindly dispenser of small presents and soothing words, she became for Peter the symbol of security in a rough-and-tumble world. After her death John and Margaret got a much-needed share of the $30,000 obtained from the sale of some of her holdings.
Only a very persistent genealogist would dare follow the fortunes of the Cooper family into the second and third generations. Six of the seven sons of Obadiah of Albany had sons named Obadiah, and it became necessary to distinguish them by middle initials. Other names also keep cropping up persistently in each generation - John, Hannah, Mary, Jacob or James, Cornelia - until the identity of any one of them becomes a difficult matter to establish. When cousins married, the situation could become a hopeless tangle. Obadiah Cooper, Peter's grandfather, had, for example, a son named Obadiah. He also had a daughter Mary, who took as her second husband Obadiah Cooper, the son of John Cooper, the oldest son of Obadiah of Albany.
Mack, Edward C. Peter Cooper, Citizen of New York. New York, Duell, Sloan and Pearce, 1949, pp. 1-3, 5-9, 11, 14, 388-389
[John Cooper, Peter's father] had set up business as a hatter in Fishkill, and was wealthy enough before the Revolution to keep some of the slaves who were then driven about in the country for sale like flocks of sheep. One of the first to enlist [in the Revolution], he served as a Minute Man and then in the militia for a total of six years, and gave a good account of himself. John Cooper's regiment built entrenchments on Governor's Island against the British. During the next year Cooper served at White Plains and at West Point defending Fort Constitution, and was present in October, 1777, at the fall of Fort Montgomery. In 1778 he voluntarily joined as a second lieutenant Captain Richard Van Wyck's company of Colonel Abraham Brickerhoff's regiment of the Dutchess County militia, and served for four years at West Point, at Highland under Governor George Clinton, and as commander of his own detachment, at Fishkill.
A big bear of a man who could lift a barrel of cider from the ground and put it in a wagon, he had all the kindness and easygoing amiability that so often accompanies size. He sold his watch for thirty dollars to help feed his destitute comrades during the war, and in his later business life extended credit to almost anyone who appealed to his generosity. As a consequence, though he was able to make money and even to prosper at times - his son referred to him at one point as a "flourishing manufacturer of hats" -, he never seemed able either to settle down in one place or to hold onto the money that he had made. Peter Cooper got not only a "glowing example of patriotism" from his father but a "warning against business carelessness and getting into debt."
Aunts and Uncles
Peter's mother was the real mainstay of the Cooper family. Margaret was educated at the Moravian School at Bethlehem, Pennsylvania, one of the best of early schools. Besides a better-than-usual education, she possessed a strong character, well fitted to keep her impetuous husband in tow and to get him out of scrapes. She was evidently imperturbable. Family tradition reports that she was gentle and tender and beautiful as well, and so short that when she went to get a cake from the cupboard she needed a footstool to reach the chair on which she stood to open the top shelf.
Both of James Cooper's children and all seven of Obadiah O. Cooper's children died in infancy, the records of their births and deaths, meticulously recorded in the family Bible, supplying a sad commentary on the uncertainty of life in the eighteenth century.
On Governor's Island one of [John Cooper's] companions had been a young man from New York City named Thomas Campbell. After the evacuation of New York City Thomas' older brother, John Campbell, fled with his wife and children north to Fishkill. On December 21, 1779, John Cooper married the latter's seventeen-year-old daughter, Margaret, at Fishkill. John Campbell [Peter's maternal grandfather] also had a son Thomas [Peter's Uncle], a boy at the time of the Revolution, whom [Peter] Cooper mentions several times in his Reminiscences but whom Hughes for some reason refers to as Samuel. A Thomas Campbell, either the brother or the son, is listed in the New York directory for 1786 as a potter. A Thomas Campbell, presumably the brother, was married in 1765 to Jemima Oakley, the sister of John's wife, and John signed the marriage certificate.
Mack, Edward C. Peter Cooper, Citizen of New York. New York, Duell, Sloan and Pearce, 1949, pp. 9-11, 14-16, 389
Peter Cooper - and everyone who has written about him - says he was the fifth of nine children. It is curious that he should have made such a mistake. If one omits his [half-]brother, he was the fifth child, but then only of eight. If one includes Martha's child he was the sixth of nine. [Similarly, if one omits the first Thomas who died at the age of eleven months, he was the fourth of seven or fifth of eight.]
With all his brothers and sisters except his [half-]brother, John [Obadiah], Peter kept up close relations. Only his [older] brother Thomas, who worked with Peter in Baltimore and later in the iron business, shared Peter's gifts as either an inventor or a businessman, with the result that Peter was forced into the role of paterfamilias to the rest of them. The Duane Street hatshop [of Peter Cooper's father, John, was] sold eventually to Peter's [older] half-brother, John [Obadiah]. [Younger] William, the rolling stone of the family, had been captain of a brick schooner on the Hudson until some time in the 'forties, when Peter handed over to him supervision of the glue factory. [Older] James became a storekeeper in Baltimore, helped Cooper with his iron business there, and later acted as his agent for collecting rents.
Peter's relation with his youngest brother, Edward, the doctor who had saved his eye after the explosion, were the saddest and the most complex. Unfortunately the vision and idealism in Peter's nature had, by one of those quirks of nature and early experience, been transmitted in grotesquely exaggerated form to his brother, who soon showed signs of fanatacism suggesting serious inner disturbance. Edward was plainly crazy, no matter how one defines the term. Edward eventually had to to be sent away to the Bloomingdale Asylum. To the very end there is no evidence that Peter ever understood that his brother was mad. Even later on, though he sorrowed for his brother's condition, he persisted in acting as if the whole thing were but a temporary and unfortunate episode.
Peter took his two [older] sisters to live in his house. They never married, and both lived to old age under Peter's hospitable roof, one dying January 21, 1850, at his Fourth Avenue home. According to Peter's grandson, one of them had been engaged to a mate on one of John Jacob Astor's ships, which sailed around the Horn and never came back; all through her life she kept a lamp burning for him in her window.
Mack, Edward C. Peter Cooper, Citizen of New York. New York, Duell, Sloan and Pearce, 1949, p. 22, 60-61, 168-172, 390Abram Hewitt's Father
By 1840, John Hewitt [Abram Hewitt's father] and Peter Cooper had been acquainted for many years, for both were loyal members of the General Society of Mechanics and Tradesmen, which had some of the characteristics of a social club. As an apprentice, young Peter Cooper knew Hewitt's little furniture business and bought lumber from him. When a little later [Peter] Cooper himself made furniture, he competed with [John] Hewitt.
Nevins, Allan. Abram S. Hewitt: with some account of Peter Cooper. New York, Harper, 1935, p. 74
It happened some  years after our marriage that my wife's sister died, and soon after her husband died also, leaving an orphan daughter who we took to bring up. Her name was Martha Clowes. After she grew up to be a woman she was courted and married  to Daniel F. Tiemann, who has since been mayor of New York City, and he made one of the best mayors we ever had, and is really and truly an honest, good and kindhearted man, who I hold in the highest possible respect. Some six years ago  we were invited to their house to witness the fiftieth year of their married life. They were married at my house. Since that time she has had ten children and she has twenty grandchildren and great grandchildren. Both are now living and well this March, 1882.
Cooper, Peter. Reminiscences
Son and Son-in-Law
At six Abram [Hewitt] entered school a few blocks away, most if not all of his elementary education being obtained at Public School No. 10, in Duane Street. The boy took a precocious delight in books. When he was eleven his father led him to the library which the General Society of Mechanics and Tradesmen had recently opened in connection with its school for apprentices in Crosby Street. In Crosby Street he was confronted with one of the richest collections in the city. At thirteen Abram entered as a free pupil the Grammar School of Columbia College. The college library of some 7,000 volumes was open to pupils. For three years Abram studied hard in the substantial school building which had been erected in 1829 on Murray Street, just behind the college; and he kept at the head of his class, taking every prize open to him. Columbia College offered some free scholarships, of which two were assigned to the New York Public School Society. Abram entered the competition examination and easily secured one. The achievement was a turning-point in his career. His father had planned to train him for a trade; but, impressed by Abram's brilliancy and fondness for books, he now approved a larger ambition. "If you want an education," he said, "you want a good one; go ahead, and I'll help you all I can."
In Columbia Abram made a mark that was long remembered by the faculty. His notes of lectures, which he preserved all his life, were remarkably systematic and complete. Hewitt, especially in his last two years, almost set a record for borrowings [from the library]. During his four years, Abram not only led his class, but excelled in forensic and literary competitions; and in doing so he gained a certain reputation in a city where most educated people took an interest in the college. He not only won four times in succession the gold medal that the college awarded for scholarship and character, but received various special marks of faculty esteem.
Yet while making this sturdy record he had to pay his own way entirely. His tuition was free and he of course lived with his parents, now established at 160 Duane Street. But he clothed himself, bought his own books, and paid all incidental expenses. He had ingenious ways of making money. He frequented the wholesale book-auctions regularly held uptown, bought volumes there at bargain rates, and hurried downtown to sell them to the retail stores. He did copying, and odd jobs for merchants. His principal resource, however, was tutoring. One of his pupils was Peter Cooper's son Edward, not quite two years his junior, who had been his classmate at Columbia but had fallen behind through sickness. This tuition was given chiefly at Peter Cooper's house, with which Abram was already familiar.
Daughter and Son-in-Law
The two youths felt the attraction of contrasting natures. Abram was brisk, decisive, boundlessly energetic, high-strung, and quick-tempered. Edward was deliberate, indecisive, shrewd rather than brilliant, full of practical sagacity, and with his father's kindly ability to make friends with everybody. They supplemented each other.
Edward Cooper, who had just graduated at Columbia, was eager for a European tour. On March 6, 1844, [Abram Hewitt] and Edward Cooper sailed. Among those who waved goodbye were Peter Cooper and his charming daughter Amelia, John Hewitt, and a group of college mates. Writing from Penkridge on April 1, [Abram] informed his family that the voyage had been delightful. He related how he finally found the graves of his grandfather and grandmother, with a handsome monument, in Penkridge. A week later he was full of wonderment over London. Late in April Edward Cooper and he shook off the soot of London for Paris. After seeing northern France, [they] travelled into Germany. As the summer ended they pushed into Italy, visiting Venice, Florence, and Rome. In October, they took passage for New York. They little guessed that they were about to sail into the jaws of death.
During the night and all day of [December] 11th [the wind] blew with what Hewitt later called inconceivable violence. The ocean seemed a vast succession of water volcanoes, spouting volumes of foam. Before dawn the upper part of the mainmast went overboard with the topsaid, and at seven o-clock the mizzen staysail followed it. "Part of the crew now got the boats ready for launching: the one a surf-boat which might live in almost any sea, the other the long-boat, which had been used for a pig-pen for ten years, was full of holes in the bottom, and in such a state of decay that no person was allowed to tread upon the planks lest the bottom should fall out. The passengers resolved to accompany the Captain in the long-boat; but such was its rottenness that we did not dare to save one particle of clothing beyond what was on our backs. The long-boat, or rather pig-pen, was launched; and as the sea was still running fearfully high, the greatest care was observed to prevent her from being dashed against the ship. God alone knows what our feelings were when we thus committed ourselves to the mercy of the raging sea, in perhaps the frailest boat that ever floated with twelve men on the Atlantic. The men, for the last three days, ate some bread. As if in answer to our prayer, the Captain exclaimed, "Sail ho!" We pass over the fearful anxiety of the two hours, during which we knew not whether she would see us or not, till we were safely on board the ship, where to our great joy we found the mate with the five men who had [taken the surf-boat]. In one hundred and ten hours we were landed safely in New York, but destitute in everything save thankfulness to God." Thereafter, he often said to his intimates, he felt that his life had been given him by God in trust; that it was his by a special dispensation, to be employed not for his own pleasure or gain, but for the good of others.
Edward Cooper and Abram S. Hewitt landed from their shipwreck in the last days of 1844 to face certain exigent demands. Abram was penniless and had to turn to the law, or something equally good, at once; Edward's father thought that he had given enough time to his education and should accept hard work and responsibilities without more delay. Edward possessed conspicuous talents of an inventive and mechanical nature, while he promised to make capable superintendent of workmen. He had all his father's geniality, kindness, and bluff ability to extract loyal effort from employees, while he grasped practical problems instantly. His father proposed to transfer the mill to Trenton and put him in charge of it. But Edward knew his own business deficiencies, and at once insisted that Abram join him in the undertaking. Peter Cooper had an ingrained fear of partnerships, but when Edward insisted, he finally yeilded, stipulating only that the two young men should set up a corporation of their own, for which he would supply most of the initial capital, and that he should have no financial responsibility for their operations save what he deliberately incurred. This arrangement was duly completed in 1845. "I don't know," Peter Cooper told Hewitt, "that you can get books far enough out of your head to let even a little business in, but if you'd like to try, here's a chance."
Amelia Cooper was not without a vein of coquetry, and knew enough to keep Hewitt in suspense. He found suitors distressingly numerous. Just when Hewitt and Amelia Cooper became engaged we do not know, but it must have been in 1850 or soon afterward. Hewitt always said that she made him wait five years before they were married; but perhaps it only seemed five years. His marriage to Amelia Cooper took place Monday, April 6, 1855, at the Lexington Avenue house, the Rev. Dr. Henry Bellows of All Souls' Unitarian Church, where the Coopers worshipped, performing the ceremony. He immediately took his wife to Trenton, where they lived the next winter, and where their first daughter was born February 28, 1856. The following spring Hewitt changed his legal residence to Ringwood, for Mrs. Hewitt, going to see it, had fallen in love with the place. Actually, they spent only the summers there, for Peter Cooper wished him and Amelia constantly at hand at 9 Lexington Avenue, and in some ways depended upon him more and more. The house was fitted up for two families, Hewitt occupying the northern half, and Peter Cooper the southern, while all the inmates took their meals together.
The note of the household from the beginning was liveliness. Both Hewitt and his wife loved to entertain. Since she was all placidity, kindliness, and practical common sense, while he was all fire and energy, they attracted different types of people. Her tastes were quietly artistic, with emphasis on painting, music, and gardening, while his were for talk and activity. They soon made Ringwood and the city house they shared with the Coopers notable for hospitality. Busy as he was, he cared little to go outside his home circle; he was no more inclined to consistent dining-out than to fishing, hunting, or theatre-going. He liked the talk of men prominent in politics and finance, and such professional men as Peter Cooper's minister, Dr. Henry Bellows. Occasionally, Mrs. Hewitt carried her unwilling husband to a party or reception. In 1857 Hewitt was elected to the Century Club. Hewitt was seldom at his best with strangers or in large gatherings, but the Century Club was a very congenial club, and he liked the special Saturday evening gatherings.
Nevins, Allan. Abram S. Hewitt: with some account of Peter Cooper. New York, Harper, 1935, pp. 19-44, 74-75, 82-83, 142-150
Peter adored his grandchildren and had a good word for each of them, from Amy ("an excellent girl of humble disposition") and Sarah ("full of life and gaiety") to Peter Cooper, later the inventor of the mercury-vapor lamp, and Edward Ringwood ("one of the nicest boys"). The old man came out and worked with his grandsons in the workshop he had built for them above the stable, and hired a professional mechanic to teach them, insisting, however, that they learn to do things for themselves. He also built a gymnasium for them in the stable. Though he occasionally preached to them on the evils of destroying the property of others or of misusing tools, a passion with Peter, he was a far more indulgent grandfather, as is usually the case, than he had been a father. In return the children loved the old man and were amused by his eccentricities. His winter shoes of rabbit fur, the new air-cushion made by his friend Mr. Goodyear, his oldfashioned razor, his practice of soaking new shoes for two months in linseed oil, his parsimonious use of old envelopes for autographs, his habit, which he though healthful, of rocking across his walking stick placed under his rocker, his going to sleep in church with his head against the column behind his pew - all came under their observant eyes, to be recalled years later. Occasionally they played tricks on him. Once small Peter Cooper and Sally, taking advantage of his softheartedness, dressed as beggars and got two dollars out of him by pouring out a sorrowful tale. When they later confessed to the imposture, he showed pleased though perhaps feigned surprise and refused to accept the return of the money.
Mack, Edward C. Peter Cooper, Citizen of New York. New York, Duell, Sloan and Pearce, 1949, p. 296Grandchildren II
PETER COOPER'S WISHES Will Be Faithfully Carried Out by His Descendants
NEW YORK, March 9. — Deeds have been signed by the heirs of Peter Cooper by the terms of which $550,000 will be added eventually to the endowment fund of The Cooper Union. This sum is the principal of the trust fund left by Peter Cooper for the support of his family. Under the agreement between the heirs, his entire estate will thus have been devoted to the institution which he founded.
Mr. Cooper's descendants and the amounts which they contribute to The Union at their death are as follows:
Edward Cooper, $100,000; Mrs. Sarah Amelia Hewitt, $100,000; Mrs. Lloyd S. Bryce, daughter of Edward Cooper, $50,000; Mrs. James O. Green, daughter of Mrs. Sarah Amelia Hewitt, $50,000; Miss Sarah Cooper Hewitt, $60,000; Peter Cooper Hewitt, $50,000; Edward R. Hewitt, $50,000; Miss Eleanor G. Hewitt, $50,000; Erskine Hewitt, $50,000.
This addition to the endowment will bring the total sum to the institution by the Cooper family up to $1,600,000, not including $510,000 given by Edward Cooper, Mrs. Sarah Amelia Hewitt and Abram S. Hewitt, for remodeling the building. The building and apparatus are valued at $1,075,000.
Los Angeles Herald, Number 161, 10 March 1899, p. 5
The Cooper Union History Project website is currently maintained by Barry Drogin. This page last updated: March 17, 2017.