Walter Bradford De Groat (1916-1988) was born and raised in Brooklyn, New York. He was the child of Walter Franklin De Groat and Margaret Marie Kennelly De Groat. in 1939 he married Elieen Isabella Crane. De Groat was a lifelong genealogist who belonged to many genealogical and historical research societies and was in touch with other genealogists around the country.
From the guide to the De Groat family genealogical research papers, 1950-1985, (The New York Public Library. Manuscripts and Archives Division.)