When Dr. John A. Slater died on July 24, 1863 at Janesville, there was no cemetery. He was buried at the foot of pine tree on the Sloss Ranch, known in later years as the Jim Peterson place.
In 1865, Slater’s two sons, Henry Hunt, age 11 and John Allen age 7, died a day apart from each, respectively on May 5 and May 6. They were buried next to their father.
There was a lot of speculation as to the cause of their deaths, some attributed to it spotted fever and others said it was poison from eating wild parsnips. What was later revealed the boys had played around the house all day and never ventured away from home. Henry was taken ill with a pain in his heal in the afternoon, and died that night. On the same evening, John was reported to have a pain in his next week and died the following morning.
In the summer of 1915, John S. Partridge, a grandson of Dr. Slater, contacted local historian Granville Pullen to move the graves to the Janesville Cemetery, which Pullen obliged.