Hi Donna; I am a descendant of the Roosa family. In your list of descendants of Dr.Antonine Crispell you listed "Gerrtje Janse Roosa". I believe this to be the same person listed in the Ulster County Genealogical Society's book I, page 29: "Families of Ulster County, The Roosa Family of Nouth America", as "Geertje Janss Roos" born 1683 and married Jan Chrispel. I am not a descentant of her but a descentant of her brother Aldert.
Farther down the tree my gggg-grandparents where Johannas Isaac Roosa, born 1773, and Lea Crispell, born abt 1780. I have very little information on Lea. They were married 14 Feb 1796 in Shawangunk RDC, Ulster Co. I would apprecate any information you may have on Lea.