Kinderen |
| 1. Cornelius Peter Nieuwkoop, geb. 4 jun 1912, Cadillac, Wexford County, Michigan, USA |
| 2. Peter Frank Nieuwkoop, geb. 30 apr 1913, Cadillac, Wexford County, Michigan, USA |
| 3. Herbert Nieuwkoop, geb. 3 apr 1914, Cadillac, Wexford County, Michigan, USA |
| 4. Thelma Bethel Nieuwkoop, geb. 8 apr 1915, Cadillac, Wexford County, Michigan, USA |
| 5. Bernard Herbert Nieuwkoop, geb. 26 feb 1916, Cadillac, Wexford County, Michigan, USA |
+ | 6. Herbert Leon Nieuwkoop, geb. 17 apr 1920, Kalkaska, Kalkaska County, Michigan, USA |
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