27 April 1701 he bought of his step-mother Jannetje Monfort and the other heirs of Pieter Monfort, Pieter's farm at the Wallabout, to which he probably removed. (Early Dutch Settlers of Monmouth County NJ by George C. Beekman) Emigrated from Amersfoort in 1631 to Long Island with his father. "William Gerretse Cowenhoven, who resided for a number of years in Brooklyn. He was a magistrate there in the years 1661-62-64, and deacon of the Dutch church in 1663. From there he removed to Flatlands. His name appears as a resident and freeholder of that place, on the assessment rolls of 1675-83-93. He was also an elder of the Dutch church there in 1677. 1 Nov 1709, he sold his farm at Flatlands to his son William, and is supposed to have spent his declining years among his ... six sons and four daughters, who were all born in Kings County, Nassau Island, as Long Island was then called... in Monmouth county." In Monmouth county after 1709
From "Early Settlers of Kings County", Bergen p. 80-81: "Resided at first in Br, of which place he was a mag. in 1661, 62, and 64, and a deacon of the R.D. church in 1663. From thence he appears to have removed to Fld, his name appearling of the patent of said town of 1667; on its ass. rolls of 1673,83, and 93; elder of its R.D. church in 1677; and taking the oath of allegiance there in 1687. Nov. 1, 1709, he sold his Fld farm to his s. William (see Lib. 5, p. 30, of Cong.) and (sup) in 1727 he removed to Monmouth Co., NJ." Issue:--Gerret Willemse, b. Jan 1, 1662; Aeltje Willemse, b. Dec 14, 1665, m. Mar. 16, 1687, Cornelis Symonse Van Aersdalen of Fld, d. prior to 1691; Neeltje Willemse, b. Feb 7, 1669, m. John Pieterse Wyckoff of Freehold, NJ; Pieter Willemse of NJ, f. Feb 12, 1671; Cornelis Willemse of NJ, b. Nov 20, 1672; Sarah Willemse, b. Dec 20, 1674, m. about 1692 John R. Schenck of NJ, d. Jan 31, 1761; Albert Willemse of NJ, b. Dec 7, 1676; Jacob Willemse of NJ, b. Jan 29, 1679; John Willemse of NJ, b. Apr 9, 1681; Annatje Willemse, b. Apr 13 or 22 1683 (sup) m. (1) Aert Willemsen, m. (2) (sup) Johannes Antonides, both of Monmouth co., NJ; William Willemse of Fld, b. Mar 7, 1686; (sup) Joris Willemse; and Jacomina Willemse, b. Dec 28, 1689, m. June 5, 1709, Elbert Williamsen of Monmouth co., NJ. Signed his name "Willem Gerretsen " and "Willem G. Couwenhoven."