This Isaac also is the ancestor of all the now-living Slings-people in Holland and the United States. His two sons Gerrit (1787-after 1842) and Johannes (1789-1833) are the leaders of two different branches which are named after the color of their hair: successively the white and the black Slingses.
The white Slingses have lived mainly till half this century in Dinteloord (many of them still are living there). The black Slingses are mainly descendants of Huibrecht Slings, who moved in 1888 to Velsen and surroundings, and in 1914 emigrated to Iowa.