Do you have a civil war pension file for one of your ancestors? If so, are you lucky enough to have a document verifying the date of death?
I found such verification in the file for Albert Hutchinson and again in the file for George Mentzer. The Mentzer file contains a statement from the undertaker for Woodson County.
Regular Sessions
First Mondays in January, April, July and October
Yates Center, Kansas
State of Kansas
County of Woodson
I, swan Johnson a registered undertaker, for the county of Woodson and state of Kansas, being duly sworn, says that he was called to attend the remains of Geo. Mentzer whose death occurred Jan. 19th 1912 and that he prepared the body for burial and knows that the death occurred as stated above.
S. Johnson.
Subscribed and sworn to before me this 3rd day of April 1912

In 1984, while a ‘novice’ genealogist, I ordered a copy of the Kansas Death Certificate for George Mentzer.
104 49
State of Kansas
State Board of Health- Div. of Vital Statistics
Standard Certificate of Death
Registered No. 24Place of Death
County: Woodson
Township: Center
City: Yates Center No. RR#2 street _____, WardFull Name: George Mentzer
Sex: Male
Color: White
Marital Status: MDate of Birth: June 12 1838
Age: 73 yrs 7 mos 6 daOccupation: Farmer
stock farmerBirthplace: Mass
Date of Death: Jan 19 1912
I hereby certify, that I attended deceased from Mch 12 1910 to Jan 19 19112 that I last saw him alive Jan 18 1912 and that death occurred on the date stated above at P.M.
The cause of death was as follows cerebral arterio-sclerosis
Duration: 3 years
Contributory Fall from Hay wagon
Singed E K Kellen[beran] M.D.
Yates Center KName of Father: don’t know
Birthplace of father: German
Maiden name of mother: don’t know
Birthplace of mother: GermanyThe above is true to the best of my knowledge
Informant: Bert Mentzer
Address: Yates CenterPlace of Burial or Removal: Yates Center
Date of Burial: Jan 22 1912
Undertaker: S. Johnson
Address: Yates CenterFiled Jan 20 1912
George Mentzer, death certificate #104 49 (19 January 1912), Kansas State Board of Health, Division of Vital Statistics, Topeka, Kansas.
L R Wallace
One of my ancestors died around 1870 after serving in the Civil War. The cause as stated in an obit was “quick consumption.” When I received his widow’s pension application file, I learned that he really died of chronic camp diarrhea, a common cause of death among 19th century soldiers.