Barent Pieteres Koijemans/Coeymans first arrived in 1639 from Utrecht, The Netherlands, with his brother Lucas. First, Barent became an apprentice at a mill owned by the Van Rensselaer family. Later, "Barent The Miller" purchased a tract of land that was given his name: Coeymans is a town in Albany County, New York, USA.
Barent married a daughter of Andries de Vos. His children were Andreas, Samuel, Pieter, Adriaentje, Jannetie and Geertie. Barent's daughter Adriaentje was born on October 19, 1672. His son Pieter married Elizabeth Greveraad on October 5, 1713. Barent died in 1710.
While Barent became known as "Barent The Miller", his brother Lucas Pieterse Coeymans became known as "De Houtsager", i.e. "The Sawyer". In 1675 Lucas bought a saw mill called "The Proesten Mill" on the east bank of the Hudson. Lucas married, too, and had a daughter Jannetje, baptised on October 19, 1684.
Sources: OpenLibrary.org, Wikipedia.org and rootsweb.ancestry.com.