Her family was a descendant of Claes Martenszen van Rosenvelt. He had came to New Amsterdam, Manhattan from the Netherlands in the 1640s. His grandsons, Johannes and Jacobus, began two branches of the Roosevelt family. Descendants of Johannes were Roosevelt family of the Oyster Bay, New York. Descendants of Jacobus were Roosevelt family of Hyde Park, New York. Eleanor was a descendant of the Johannes branch. Her future husband, Franklin was descended from the Jacobus branch.