After the Civil War began, on August 30, 1862, Elijah joined Company I (i) of the 81st Regiment, Ohio Infantry volunteers at Greenfield, OH. His wife and family may have gone to live with her parents.
Elijah's pension file contains an affidavit from a Mrs. J. A. Matthews, dated Nov. 10, 1916. Mrs. Matthews at that time was a resident of Parsons, Labette Co., Kansas. She states:
"I was personally acquainted with Margret (sp) Davis, wife of Elijah G. Davis, deceased, of Co. I 81st Ohio Infantry, and as a girl lived near their home in Greenfield, Ohio. They were our nearest neighbors, and I was at their home almost every day when the family was sick of diphtheria. Mrs. Davis and her sister Mary and her two children all died within the space of a few days and they were buried at the old cemetery near the old Presbyterian church near Greenfield. I did not attend the funeral but I know she was buried at that place. ...The cemetery is on the hill just above Paint Creek. Every one was afraid to go near the family on account of the disease. I helped to prepare Mrs. Davis for burial. I do not know whether their graves are marked or not. She died at the home of her father, and further this deponent saith not."