Individual Details

The Early Dutch Settlers to Monmouth County NJ, gives the birth date of Cornelius as 20 Nov 1672. This doesn't agree with the calculations from his tombstone inscription which would place his birth in November of 1671, and indeed those calculations perhaps place his birth a bit to close to his brother Peter.

http://distantcousin.com/obits/nj/1800/1898/may/18/earlydutchsettlers.html
Early Dutch Settlers to Monmouth County, New Jersey - Part 9
Cornelius Couwenhoven, the father of thirteen children, made his will November 22d, 1735. It was proved June 22d, 1736, and was recorded in the office of the secretary of state at Trenton in Book C of Wills, page 107. He mentions the names of all of the above children, but the spelling differs considerably from mine. For instance he spells Jacomintje as "Yacominsky," and Janetje as"Yannikie."
He devises to his son William the land sold to him by William Bowne by deeds dated March 1st, 1704, and January 20th, 1705, one for 94 ½ acres and the other 62 acres, and also 120 acres released to him by Daniel Hendrickson, Garret Schenck, John Schenck and Peter Wyckoff, dated July 10th, 1716.
Cornelius Couwenhoven and his wife are buried in the Schenck-Couwenhoven burying ground. The inscription on his tombstone shows that he died May 16th, 1736, aged 64 years, 5 months and 17days. His wife, Margaretta Schenck, died December 6th, 1751, aged 73 years, 9 months and 27 days.
Source: Red Bank Register, Wednesday, May 18, 1898

Find A Grave Memorial# 30378907
Buried Schenck-Couwenhoven Cemetery, Pleasant Valley, Monmouth County, NJ
Here Lyes Interr'd the Body of Cornelus Cowenhoven who Departed this life the sixteenth of may Anno Domini one thousand seven Hundred thirty six Aged sixty four years five(?) months. Number of days not visible - stone has sunk into the ground.

Transcription of Will found in a family tree on Ancestry.com:
WILL of Cornelis Willemse Van Kouwenhoven
In the name of God, Amen, the twenty-second day of November in the year of our Lord, One-Thousand, Seven-Hundred and Thirty-Five, I Cornelius Covenhoven of the Township of Middletown in the County of Monmouth in the Eastern Division of the Province of New Jersey Yeoman, being sick and weak in body but of sound and perfect mind and memory, provided he, God, therefore calling unto mind the mortality of my body and knowing that it is appointed for all men once to dye,do make and ordain this my Last Will and Testament. That is to say, principally and first of all, I give and recommend my soul into the hands of God that gave it, and my body I recommend to the Earth to be buryed in a Christian-like decent manner at the discretion of my executor and executrix hereinafter named, nothing doubting but of the general resurrection I shall receive the Lord again by the mighty power of God to bless me in this life, I give, devise and dispose of the same in manner and form following:
Imprimis, my will and desire is that all my legal debts and expenses of my funeral be paid and discharged.
Item. I hereby give and devise unto my loving wife Margaret the use of all my estate, both real and personal wherewith I am now invested and not hereafter in this my will given away or disposed of to any other person, to her own proper life and benefit so long as she shall remain my widow, for her own maintenance and to bring up and educate her children upon. About my old Negro woman Hannah, I give to my said wife during the term of her natural life, and after my said wife is deceased, then the said Negro wench is to be declared as part of my personal estate.
Item. If my said wife shall see cause to remarry after my decease, then I hereby give her my best bed and furniture, my best cupboard and best riding horse with a stable with as good an outlet as I have given to any of my daughters, with six sheep, all to be levied out of my estate for her use which bequest with the use of my Negro wench above named for the (illegible) of my said wife in lieu of her Thirds and Doury. But my will and desire is in case my said wife shall remarry and outlive her other husband, and he doth not make a suitable provisions for her, that then my two sons, William and Roeloffe, shall in consideration of what I have given them in this my Last Will, maintain their said mother equally between them so long as she shall live.
Item. I hereby give my son William the sum of twenty shillings, which sum I give him as my eldest son.
Item. I hereby give the Negro called Sam, which I formerly let my said son William have, I hereby give the said Negro, Sam to the wife of my said son William and his assigns for ever.
Item. I hereby give the Negro called James which I have let my son Roeloffe have, I hereby give the said Negro James to the wife of my said son Roeloffe and his assigns for ever.
Item. I hereby give my Negro Toney to my son Roeloffe to take him into his possession for the benefit of him and his assigns when my wife shall either remarry or depart this life, which shall first happen.
Item. I hereby give my Negro Tom to my son William to take him into his possession for the benefit of him and his assigns when my wife shall either remarry or depart this life, which shall first happen.
Item. My desire is that all my daughters that is now unmarried shall have as good an outlet to be levied out of my estate to each of them as their several sisters before them hath had.
Item. My will and desire is that all my daughters that hath had Negro wenches from me that they severally keep the said several Negro wenches now in their possession until each Negro wench shall arrive at the age of eighteen years, and then that each Negro wench be sold or valued by suitable appraisers at such age to their value that such sums of money as they shall severally fetch be deemed part of my personal estate and equally divided amongst my children, share and share alike.
Item. My will and desire is that upon the death of my wife or her remarriage, which shall first happen, that all my moveable estate shall be equally divided amongst my children, share and share alike and if any of my children shall happen to die, then their shares to be divided equally amongst the survivors or survivor of them. But my desire is that my daughter Allkye be maintained out of my estate as long as she remains a widow.
Item. I hereby give an bequeath to my son William all those tracts of land sold to us by William Bowne by his deeds bearing date, the last of March 1704, and the 20th of January 1705, one for ninety-four acres and a half and the other for thirty-two acres and the one-hundred and twenty acres of land released to us by Daniel Hendricks, John Schenck, Garret Schenck and Peter Weycoffe by their release date of July 18th 1716. To have an to hold the said several tracks and parcels of land to him my said son William, his heirs and his assigns forever, to be taken into his possession when my wife shall either remarry or depart this life, which shall first happen.
Item. I hereby give an bequeath to my son Roeloffe the whole residue of the land and meadow beside the one-hundred and twenty acres herein before given to my son William that is released to us by the before mentioned from Daniel Hendricks, John Schenck, Garret Schenck and Peter Weycoffe, together with two acres and a half of land that was confirmed to us by James Hubbard and his wife Rachel by the then deed dated 27th of July 1706, and the two acres that was confirmed to me by Jonathan Holmes by his deed dated June 23rd 1719, and the ten acres that was confirmed to me by John Bowne by his deed dated 4th of May 1703, and the one-hundred and twenty-five acres released to me by Garret Schenck and John Schenck by their deed dated December 24th 1700. To have and to hold the said several tracts and parcels of land and meadow as above mentioned to him my said son Roeloffe, his heirs and assigns forever, to be by him possessed at my wife's remarriage or death, which shall happen first.
Item. My will and desire is that my son William shall in consideration of the land herein before given him at his taking possession thereof shall pay the first sum of fifty pounds to my daughter, Leah, and one year from that date, the sum of fifty pounds of like money to my daughter, Catherine, and a year after that the sum of fifty pounds of like money to my daughter, Jacomyntje and a year after that the sum of fifty pounds of like money to my daughter, Margaret and a year after that the sum of fifty pounds of like money to my daughter, Rachel, and in case any of my said daughters shall dye before their money shall become payable to them, such part to be divided amongst all my living children, sons and daughters share and share alike.
Item. My will and desire is that my son Roeloffe shall in consideration of the lands herein before given to him at his taking possession thereof shall pay the sum of fifty pounds to my daughter, Mary and one year after that date, the sum of fifty pounds of like money to my daughter, Sarah and a year after that the sum of fifty pounds of like money to my daughter, Neeltje and a year after that the sum of fifty pounds of like money to my daughter Annetje and a year after that the sum of fifty pounds of like money to my daughter, Alltje and a year after that the sum of fifty pounds of like money to my daughter, Anna and a year after that the sum of fifty pounds of like money to my daughter, Jacomyntje, and in case any of my said daughters shall dye before their money shall become payable to them, such part to be divided amongst all my living children, sons and daughters share and share alike.
Item. I hereby nominate, constitute and appoint my loving wife Margaret Couvenhoven and my sons William Couvenhoven and Roeloffe Couvenhoven to be executors and executrix of this, my Last Will and Testament to be the same duly performed. And I do hereby utterly disallow, revoke and disclaim all and every other former Testaments, Wills, Legacies, and Executors by me in any ways before this time made/willed and bequeathed. Ratifying and confirming this and no other to be my Last Will and Testament, and in witness whereof I have herein let my hand and seal the day and year first above written.
Signed, sealed, published, pronounced and declared by the said Cornelius Couvenhoven to be the Last Will and Testament in the presence of us:
Garret Schenck
Johannie Bennet
Robert Doosworth

Be it remembered that on the twenty-second day of June 1736, personally and before me Lawrence Smyth Surr duly delegated and appointed Johannie Bennet and Robert Doosworth, two of the subscribing witnesses to this Will who being solemnly sworn on this day that they and Garret Schenck saw Cornelius Couvenhoven sign and seal and heard him publish this instrument to be his last Will and Testament and that they and the other witnesses subscribed their names hereto in the testator's presence at his request.
Sworn before me
Be it remembered that on the day and year above, personally came before me Lawrence Smyth, William Couvenhoven, Roeloffe Couvenhoven, Executors, and Margaret Couvenhoven, Executrix in this said Last Will and Testament named and appointed who were sworn to the due execution and performance thereof.
Copy of the Will of Cornelius Couwenhoven is from a posting on the website of David Kip Conover. (Well documented informative site)

Birth	20 Nov 1672	Kings County, Nassau (Long) Island, New York
Marriage	8 Sep 1700	Flatlands, Kings County, Long Island, New York - Margaretta Schenck
Death	16 May 1736	Middletown, Monmouth County, New Jersey
Burial		Schenck-Couwenhoven Cemetery, Pleasant Valley, Monmouth County, New Jersey

Spouse	Margaretta Schenck (1678 - 1751)
Child	William Couwenhoven (1700 - 1755)
Child	Altje Couwenhoven (1701 - )
Child	Leah Couwenhoven (1702 - )
Child	ANNETJE Couwenhoven (1703 - 1759)
Child	Neeltje Couwenhoven (1705 - )
Child	Roelof Couwenhoven (1706 - )
Child	Jannetje Couwenhoven (1708 - )
Child	Maria Couwenhoven ( - )
Child	Saartje Couwenhoven (1711 - )
Child	Rachel Couwenhoven ( - 1801)
Child	Margaret Couwenhoven ( - )
Child	Jacometje Couwenhoven ( - )
Child	Catarina Couwenhoven ( - )
Child	Helena Couwenhoven ( - )

Father	Willem Wolfert Gerritse Couwenhoven (1636 - 1728)
Mother	Jannetje Pieterse Monfoort (1646 - 1723)
Sibling	Altje Couwenhoven (1665 - )
Sibling	Neeltje Couwenhoven (1667 - )
Sibling	Peter Couwenhoven (1671 - )
Sibling	Sarah Willemse Couwenhoven (1674 - 1761)
Sibling	Albert Williamse Couwenhoven (1676 - 1748)
Sibling	Jacob Willemse Couwenhoven (1679 - )
Sibling	Jan Willemse "John" Couwenhoven (1681 - )
Sibling	Annetje Couwenhoven (1683 - )
Sibling	William Willense Couwenhoven (1686 - 1769)
Sibling	Jacomma Couwenhoven (1689 - )