| Birth | September 5, 1902 36 27 |
| Birth of a brother | Walter Martens November 17, 1903 (Age 14 months) |
| Birth of a sister | Nora H. M. Martens April 16, 1906 (Age 3) |
| Birth of a brother | Bernard Martens 1907 (Age 4) |
| Death of a brother | Bernard Martens 1907 (Age 4) Cause: Crib death |
| Birth of a brother | Arnold Martens 1909 (Age 6) |
| Birth of a brother | Bruno Martens 1909 (Age 6) |
| Death of a brother | Arnold Martens 1909 (Age 6) Cause: Crib death |
| Death of a brother | Bruno Martens 1909 (Age 6) Cause: Crib death |
| Birth of a brother | Henry Martens Jr March 12, 1910 (Age 7) |
| Birth of a brother | Alan Martens April 28, 1911 (Age 8) |
| Death of a brother | Henry Martens Jr 1911 (Age 8) Cause: Pneumonia |
| Birth of a brother | Edmund F. Martens April 30, 1912 (Age 9) |
| Birth of a sister | Marie Martens February 14, 1913 (Age 10) |
| Death | 1913 (Age 10) Cause of death: Ruptured appendix |
| Family with parents |
| father |
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| mother |
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| elder sister |
Anna Elisa Martens Birth: November 4, 1896 30 21 — Iowa, USA Death: May 28, 1969 — Washington, USA |
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19 months elder sister |
Ulinka Martens Birth: May 23, 1898 32 22 — Iowa, USA Death: 1935 — South Dakota, USA |
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11 months elder sister |
Amanda Martens Birth: April 18, 1899 32 23 — Iowa, USA Death: July 21, 1976 — South Dakota, USA |
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3 years himself |
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14 months younger brother |
Walter Martens Birth: November 17, 1903 37 28 — Iowa, USA Death: 1914 — Iowa, USA |
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2 years younger sister |
Nora H. M. Martens Birth: April 16, 1906 39 30 — Remsen, Plymouth, Iowa, USA Death: July 8, 1986 — Scottsdale, Maricopa, Arizona, USA |
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21 months younger brother |
Bernard Martens Birth: 1907 40 31 — Iowa, USA Death: 1907 — Iowa, USA |
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3 years younger brother |
Arnold Martens Birth: 1909 42 33 — Iowa, USA Death: 1909 — Iowa, USA |
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1 year younger brother |
Bruno Martens Birth: 1909 42 33 — Iowa, USA Death: 1909 — Iowa, USA |
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14 months younger brother |
Henry Martens Jr Birth: March 12, 1910 43 34 — South Dakota, USA Death: 1911 — South Dakota, USA |
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14 months younger brother |
Alan Martens Birth: April 28, 1911 44 35 — South Dakota, USA Death: December 8, 1963 — South Dakota, USA |
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1 year younger brother |
Edmund F. Martens Birth: April 30, 1912 45 36 — South Dakota, USA Death: January 1974 — La Crosse, La Crosse, Wisconsin, USA |
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10 months younger sister |
Marie Martens Birth: February 14, 1913 46 37 — South Dakota, USA Death: September 20, 1980 — South Dakota, USA |
| sister |
Private |
| sister |
Private |
| Media object | Franz Martens.jpg Format: image/jpeg Type: Photo Highlighted image: yes |
| Media object | Franz Martens.jpg Format: image/jpeg Type: Photo Highlighted image: yes |
| Media object | Franz Martens.jpg Format: image/jpeg Type: Photo Highlighted image: yes |
| Media object | Franz Martens.jpg Format: image/jpeg Type: Photo Highlighted image: yes |
| Media object | Franz Martens.jpg Format: image/jpeg Type: Photo Highlighted image: yes |