My roots are all from the NYC area. I know that my gggrandfather--Johann Dankert--came to NYC in 1868 with his wife Sophie. They had three children: Charles, Josephine, and Frederick (the latter was my ggrandfather). I haven't yet determined where in Germany they were from, though I've narrowed it down to Mecklenburg-Schwerin. The only thing we have from Johann (John, as he was always known to us) is a letter from his brother Christian in Germany (Dabel), written in 1883.
This sums up all I know. If anyone can come up with any connection, please let me know.