What do you want to find now?Frederick's and Marie's parents?
You could try locating the family in the 1900 census. This would give you an idea of where Frederick and Marie were born and where their parents were born...
Their marriage certificate should have their parents' names.
Here's a possible match for Frederick in the New York Census: Year Surname Given Name (s) County State Page Township or Other Info Record Type Database ID# 1870 REIN FREDERIC Westchester County NY 427 New Rochelle Federal Population Schedule NY 1870 Federal Census Index NY30737393