I went to Loman Family Tree and on his fact information: source: 'Pension Application'
After Harvey Isaac's death his third wife Viola applied for a pension for his service in the Civil War. The application had a question reguarding previous marriages for Harvey. In the answer for that question is listed Caldonia Linn died July 1876.
Elizabeth Caldone Parker, born 1839 in Tennessee; death: July 1876 in Illinois.
She may be buried with or near James Harvey Isaacs. Either in Frankfort or in Sesser, Franklin County Illinois.