Written on the back of this post card photo is "To Sadie From Oll & Ethel". "Oll" and Sadie were first cousins, he was 12 years younger than she.
Oliver Benjamin Negley was the son of John Calvin and Mary Negley and was born June 3, 1892. He married Ethel Alice Kier December 18, 1912. They had two daughters, Hazel and Freda. Hazel was born in 1914 and if that little girl looks about 3 years old, that would mean the photograph was taken about 1917. Oliver signed his WWI draft registration card on June 7, 1917. He claimed exemption from draft due to his wife and child, so I don't believe he served (I don't subscribe to Fold3 to check on that).
In the Decatur Cemetery, Decatur, Iowa I found this grave for Oliver and, I assume, his wife. I can't explain why her name is "Louva H", not "Ethel". Ethel was with Oliver yet in the 1930 census, but I can't find them at all in 1940. I don't find any marriage record for Oliver and Louva. If you know the story, please leave a comment!