There is a Degroot in the Avondale section of Nutley (Franklin)on the 1881 Land Ownership Map. Adjacent to the property is Mrs. C. M White, and C. M. White. These are my GGG grandparents. Mrs. White, born Frances "Fanny" Wilson, had a step-father at the time of her marriage named W. H. Degroot. He would have married the widow Emma Wilson, originally of England. I do not know her maiden name.
I do not know if the Degroot on the property map and the Degroot that was the step father was the same Degroot. I believe that W. H. Degroot also served in the Civil War.
Does any of this ring any bells?
Leslie