The above (from the Indiana Genealogical Society's Records Preservation Project for Hendricks County), is an example of the kind of genealogy gems that you can unearth in probate records. This affidavit, stating that they died on July 23, 1857, is part of the process of the probate court appointing an administrator for the estate of the deceased.
Once appointed, the administrator would pay any bills owed by the estate and then submit the receipts to the court. The bills for the funeral and burial are often among those receipts. In the example below, the receipt for the tombstone gave not only the dimensions and the name and 1858 date of death to be inscribed, but even the sad verse that was to accompany it:
Even people who wrote wills before they died could have a probate record--in those instances, the court would recognize their executor instead of an administrator. So make sure you keep this resource in your research toolbox!