Jan was born at his parents plantation near the Wallabout and in what is now the borough of Brooklyn.
He was baptized on February 23, 1648 in the Reformed Dutch Church of Niew Amsterdam. In adulthood he would be
living in an area known as Amersfoort/Flatlands on Long Island. Soon after purchasing land, he married a
neighbor girl, Ida Brinckerhoff. They were married sometime in 1687 at the Flatlands Reformed Church. Ida was the daughter
of Abraham and Aeltje Strycker Brinckerhoff. The Brinckerhoffs owned a large farm near Flushing Bay in the vicinity
of Jamaica. Ida was about 19 when she married the 40 year old Jan Monfoort and apparently this is his first marriage.
Jan was a farmer, rarely interested in public office as was his father. However he did serve as assessor in 1704
for Jamaica, Long Island. He and his wife would later move to what is now called Great Neck about 1705.
They would become the parents of 7 children...Peter, Abraham, Sara, Aeltje, Susanna, Jacobus, Lammetje.
No date of death has been found for Jan or his wife, but he did make out his last will and testament in Aug of 1720.
He was last named as a witness to the birth and christening of a granddaughter, Yda, daughter of their son Peter and his wife,
Sara Luyster Monfoort. This took place in March of 1721. He may have died by 1725, as he is no
longer listed in any records, either in the church or legal records.