Son of Heinrich Christoph Friederich August Oestmann and Ida Maria Dorothea Christine Hogrefe.

February 27, 1908, St. Paul (Stutheit)Lutheran Church south of Johnson, Nebraska - Married Emma Anna Stutheit, daughter of Friedrich Heinrich Stutheit and Friedericke Sophia Moerer.

Children
1. Arnold Heinrich Friederich Oestmann, 1909–1982, married Junita Evelen Michel.
2. Erhardt Ernst Siegmund Oestmann, 1911–1982, married Alberta Marriett Emmaline Stutheit
3. Elta Friedericia Ida Oestmann, 1912–1995, married Herman Henry Hermann Bohling
4. Norvel Herman Otto Oestmann, 1914–1999
5. Werner Heinrich Oestmann, 1915–1967, married Luella Christine Bohling
6. Hulda Frieda Oestmann, 1917–1947, married Arnold Frederich Heitman
7. Herbert Emil Carl Oestmann, 1919–1919
8. Wilbert Franz Emil Oestmann, 1920–1982, married Marie Anna Gebers
1926–2003
9. Melvin Johannes Ernst Oestmann, 1921–1982
10. Lorena Louise Christina Oestmann, 1912–1995, married Harold August Herman Kniep

Obituary - Johnson News dated Dec. 14, 1939.:

Otto Henry Oestmann, life-long resident of this community died at his home Sunday. Immediate cause of death was grippe and complications.

Mr. Oestmann was 58 years, 7 months and 5 days old at the time of his death. He was born in Nemaha County May 5, 1881, a son of Henry O. Oestmannand Ida Hogrefe Oestmann. For a number of years Mr. Oestmann had been a semi-invalid, as a result of arthritis. Despite this handicap, he was of a cheerful and friendly disposition, with countless friends.

Services were held at the home and at Hickory Grove Cemetery Wednesday. A large crowd attended the services for Mr. Oestmann.

He is survived by his wife and nine children. An extended obituary will appear in the News next week. They had 10 children, one preceded him in death.