When John Jacob Dumolt was born on 30 September 1885, in Billingsville, Boonville Township, Cooper, Missouri Territory, United States, his father, Michael Dumolt, was 35 and his mother, Anna Katherine Esser, was 29. He married Dorothy Knauer on 14 September 1910. They were the parents of at least 2 sons. He lived in Boonville Township, Cooper, Missouri, United States in 1900. In 1940, at the age of 54, his occupation is listed as mechanic, city garage in Kansas City, Jackson, Missouri, United States. He died on 22 November 1971, in Kansas City, Jackson, Missouri, United States, at the age of 86.