Elmer John Hammer

https://www.findagrave.com/memorial/52926340
https://www.familysearch.org/tree/person/details/KFJB-3Y5

ELMER JOHN HAMMER was born March 5, 1894 in Bangor Twp, Marshall Co., Iowa and died Dec. 26, 1968 in Santa Ana, Calif. On Feb. 26, 1913 in Marshall County he married (1) EDNA MARGARET WALTERS, born May 4, 1892 in Franklin County, Iowa, died July 14, 1978, daughter of Matt Walters and Jennie Hensicks (or Hendricks). On Feb. 16, 1934 in Des Moines he married (2) IVA SWANSON SMITH, born in 1893 in Marshalltown, Iowa, and died in 1987, daughter of Pete Swanson and Esther McCurdy. Iva had no children. Elmer’s second wedding certificate listed his occupation as farmer.
I have seen Edna's maiden name spelled as both Walters and Walter.

Obituary: Rites Monday for Elmer Hammer
Funeral services will be held Monday, Dec. 30 at: 1:30 p.m. from the Biersborn Funeral Home in Union for Elmer Hammer, 74, a former Union resident who died Thursday morning, , Dec. 26, at his home in Santa Ana, Calif.
The Rev. Ron Johnson, pastor of the Church of Christ in Union, will officiate. Interment will be in the Miller Cemetery, southwest of Union. The body was scheduled to arrive at the Biersborn Funeral Home Sunday.
Survivors include his wife; one daughter, Mrs. Lewis Price of Wellsburg; five sisters, Mrs. Eva Newton of Pocahontas, Wisc., Mrs. Hattie Bittner, Mrs. Frank Teske and Mrs. Luella Peterson, all of Des Moines, and Mrs. LaVera Higgason, of Eldora; and one brother, Verlin Hammer of Marshalltown. His parents preceded him in death.

Child of ELMER HAMMER and EDNA WALTERS:
Aurella F. Hammer Price 1913–1995

I think Aurella was their only child, despite others mentioned below. Aurella is the only child shown in the 1930 census and the only child mentioned in both parents' obituaries.

https://www.familysearch.org/tree/person/vitals/KFJB-3Y5
Children according to familysearch.com:
Earl Dean Hammer 1910–Deceased G95P-VL5​​
Aurella F. Hammer 1913–1995 G95P-PFL​​
Howard Hoover Hammer 1918–2010 G95P-535

Siblings:

1. Carrie May Hammer McCollum Rowley 1888 - 1921 https://www.findagrave.com/memorial/53305992
2. LaVera Mina Hammer Higgason 1890 - 1975 https://www.findagrave.com/memorial/52798911
3. LaVada Ina Hammer Bittner 1890 - 1963 https://www.findagrave.com/memorial/53304452
4. Elmer John Hammer 1894 - 1968 https://www.findagrave.com/memorial/52926340
5. Harriett Dell Hammer Bittner 1896 - 1990 https://www.findagrave.com/memorial/53158040
6. Eva Elizabeth Hammer Newton 1898 - 1975 https://www.findagrave.com/memorial/92331230
7. Bethel Lena Hammer Teske 1902 - 1990 https://www.findagrave.com/memorial/127940734
8. Luella Jane Hammer Peterson 1906 - 1988 https://www.findagrave.com/memorial/103938057
9. Verlin Jennings Bryan Hammer 1908 - 1986 https://www.findagrave.com/memorial/53159152

1930 Census:
Name Role Sex Age Birthplace
Elmer J Hammer Head M 37 Iowa
Edna M Hammer Wife F 37 Iowa
Aurella F Hammer Daughter F 16 Iowa
Event Place: Eldora, Hardin, Iowa, United States
Household ID: 39
Line Number: 69
Sheet Number and Letter: 2B
Affiliate Film Number: 657
Affiliate Publication Number: T626
Affiliate Name: The U.S. National Archives and Records Administration (NARA)
Digital Folder Number: 004950809
Microfilm Number: 2340392
Image Number: 01020
Indexing Batch: N03793-4
Citing this Record: "United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XMJD-JJH : accessed 3 June 2021), Elmer J Hammer, Eldora, Hardin, Iowa, United States; citing enumeration district (ED) ED 8, sheet 2B, line 69, family 39, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 657; FHL microfilm 2,340,392.

Birth record:
Name Elmer John Hammer
Sex Male
Birth Date 5 Mar 1894
Birthplace Iowa, United States
Father's Name Adam M. Hammer
Father's Sex Male
Mother's Name Eliza E. Rash
Mother's Sex Female
Event Type Birth
Certificate Number v3 p108
Digital Folder Number 004309539
Microfilm Number 956743
Image Number 00124
Indexing Batch I10765-8
Collection Information: Iowa, County Births, 1880-1935
Cite This Record:
"Iowa, County Births, 1880-1935," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:KHTF-GZC : 1 April 2020), Elmer John Hammer, 5 Mar 1894; citing Iowa, United States; county district courts, Iowa; FHL microfilm 956,743.